There was one at the RAF museum in Hendon, London, but this is currently at the museum at Cosworth undergoing refurbishment.

When Japanese pilots of the Akeno school tested the Goshikisen against the Hayate, it could hold it's own even when out-numbered 3 to 1 in mock combat!
That doesn't show up in the spec sheet.
Only so much can be conveyed on paper where the Ki84 looks so good. The Nakajima only had the advantage of top level speed and dive rate up to 496 mph (the Ki100 could then keep diving another 30+ mph faster, however) due to it's streamlined design but the Kawasaki was stronger and more stable at terminal speeds (the Ki 84 also had more trouble with aerobatics especially at high speed than the Ki 100 with it's lighter controls as well as better climbing turns).
Still, 3 to 1 says a lot (when they rotated planes and all were among the best pilots).

The Japanese used the airframes from the KI-61's, whose engines were totally unreliable, and had plans from Germany sent to them on their Focke Wulf 190A fighters which incorporated a BMW 801 radial onto a narrow fuselage. When the Japanese used this technique they found that with the Kawasaki Ha 140 engine giving 1500 horsepower, they had a real thoroughbred on their hands. True the cowling was large, but the radiator was offset and narrowed and with the narrowness of the fuselage along with a narrow to wide spinner cap the aerodynamics was much improved. The K-100 was easy to fly and gave even the most novice pilot a fighting chance. Problem with the KI-84 considered by many to be the best Army fighter of the war was that she suffered from fuel line clogs and ruptures and since as the war was turning badly much fuel the Japanese used was unrefined, as evident by the Carrier Taiho tragedy, the true beauty of both fighters couldn't be appreciated until they were bought to the states and tested with Imperial fuel. In these post war tests the Ki-84 was 3 mph faster than the P-51 , 17 mph than the P-47 and 22 mph faster than the P-40. This considered that pilot armor and self sealing tanks were used the KI-84 was judged the best Japanese army fighter and the KI-100 the best Jap fighter of the entire conflict. Amazing feat for a aeronautical industry being bombed daily as the Japanese were building these fighters in underground factories right till the end of the war!

The Japanese used the airframes from the KI-61's, whose engines were totally unreliable, and had plans from Germany sent to them on their Focke Wulf 190A fighters which incorporated a BMW 801 radial onto a narrow fuselage. When the Japanese used this technique they found that with the Kawasaki Ha 140 engine giving 1500 horsepower, they had a real thoroughbred on their hands. True the cowling was large, but the radiator was offset and narrowed and with the narrowness of the fuselage along with a narrow to wide spinner cap the aerodynamics was much improved. The K-100 was easy to fly and gave even the most novice pilot a fighting chance. Problem with the KI-84 considered by many to be the best Army fighter of the war was that she suffered from fuel line clogs and ruptures and since as the war was turning badly much fuel the Japanese used was unrefined, as evident by the Carrier Taiho tragedy, the true beauty of both fighters couldn't be appreciated until they were bought to the states and tested with Imperial fuel. In these post war tests the Ki-84 was 3 mph faster than the P-51 , 17 mph than the P-47 and 22 mph faster than the P-40. This considered that pilot armor and self sealing tanks were used the KI-84 was judged the best Japanese army fighter and the KI-100 the best Jap fighter of the entire conflict. Amazing feat for a aeronautical industry being bombed daily as the Japanese were building these fighters in underground factories right till the end of the war!

Additional note from the Akeno flying school:
The ascendency in the turn and climb was the edge over the Ki 84. How this could be is puzzling because the climb per minute goes to the Frank (unless it suddenly lost power to the unreliable engine). The straight leading edge wing design helps in the turn for the Ki 84 also. But the Ki 100 was less work to trim for the pilot and was much more stable. Though less powerful, it may have had better roll and reflexes in the first seconds of a climb or turn I guess.
In addition to losing the 6-700 lbs in trading engines of equal power, it also shed the ballast in the tail. So the Tony was feeling it's oats now and the pilot could be confident in the reliable motor.

From what I have read to date, roll rate, acceleration and high altitude performance are what set this Kawasaki apart from the other Japanese fighters.

Relatively slow for the period but manouverable,reliable and easy to fly

Essentially the Ki-61 "Hien" fighter re-worked to take an air-cooled radial engine and fitted with an all-round visibility canopy. A good fighter plane, but another case of too-few-and-too-late.

I REBUILT THE 4 BLADE PROP, FOR CHAMPLIN FIGHTER MUS. ARIZONA FOR THE SMITH. AND WE THOUGHT THE PROP WAS OF GERMAN DESIGN, AND THAT GOES TO, THE MODS , THEY WERE DOING TO MAKE THIS A BETTER PREFORMER. WHEN FINELLY GETTING APART, WITH GREAT DIFFICULTY, I FOUND THE BALL BEARINGS WERE POWDER, BUT THE RACES WERE VERY GOOD. I CAME TO THE THOUGHT THAT WE HAD BOMBED THE GERMAN BALL BEARING PLANTS IN GERMANY, AND THIS PROP WAS BUILT WITH INFERRERER MATERAL IN THE BALLS. I REPLACED WITH APPROX 3/8, AND 5/16 SIZE. OVER 100 5/16 AND APROX 80 3/8. DON'T REMEMBER THE METRIC SIZE. SO IF WE COULD KNOW DATE WE BOMBED. THIS PROP WAS BUILT AFTER THAT . DATEING THE TIME OF MANIFACTURE. JUST ONE MORE PIECE OF THE PICTURE..............

"During March and April 1945 experienced instructors from the Akeno Army Flying School flew the Ki-100 in extensive tests against the Ki-84, which was considered to be the best of the JAAF fighters then in operational service. Their conclusions were that, given pilots of equal experience, the Ki-100 would always win in combat."
Unquote. For those who require a more faithful rendition of my posted paraphrase earlier that drew lightning.
I'm just the messenger. The thrust of my post was right if admittedly overboard. The point is virtually the same: The Ki 100 would 'always' win in combat in their opinion (based on tests flown 'against' the Ki 84).
I wish they would elaborate but nooo.
My reasoning would be that the Ki 84 required a more skilled
pilot with all that hp. If the Ki 43 and 44 were a handful to trim during a dogfight - with reliable engines, imagine an unreliable 2,000 hp beast! Far more pilot intensive than the stable and reliable handling of the 1500 hp Ki 100.
It's stability advantage of the Ki 100 is demonstrated by comparing level maximum speed and terminal 'permitted' dive speed.
The Ki 84 on japanese fuel did at least 388 mph vs what? 367 mph for the Ki 100?
But terminal dive was the opposite! The Ki 100 overhauls the Ki 84: 528 mph vs only 496 for the Ki 84. That's a 53 mph swing in favor of the Ki 100!
Certainly the build of the Kawasaki Goshikisen was tough but that of the Hayate wasn't so far behind.
It was mostly the stability of the Kawasaki design that the dive reveals by all written accounts. A big factor for inexperienced combat pilots in 1945.

The enlarged tail and horizontal stabilizer of the Ki 61-II Kai immediately transformed it's flight characteristics vs the earlier Ki 61-II; and the Ki 61 wing profile was better than that of the Ki 84 at higher speeds as in diving maneuvers and handling (to amend my last post).
The Ki 100 was the beneficiary. 'Maximum permissible diving speed' was 528 mph for the Ki 100 and it held it's speed after pull out! That's probably faster than any Japanese fighter but the Ki 61.
Up to 23,000' it was superb and potentially the master of all opposing fighters except the P-51D which made a good 'ferocious' fight depending on pilot skill for the outcome. But at higher altitudes performance fell rapidly.
It's life span was short and sweet: 10 months from conception to surrender.

Some say the straight leading edge of the Nakajima wing was not as good as the Kawasaki wing for handling in aerobatics.
The Ki 100 was also said to have good power of maneuver.

I found out that handling was sweeter because the fuel tank was moved from behind to in front of the pilot when the radial replaced the inline on the Tony. Evidently the change in cg was favorable. If it utilized a wing of increased area as some say, that would enhance handling directly.
Wikipedia has the comment about the edge the Ki 100 had over the Ki 84 in a dogfight in the opinion of their test pilots. If the Hayabusa was a handful to trim ...etc compared to the Reisen, perhaps the Hayate was even more labor intensive with the tempermental engine vs the Goshikisen pilot's plane. Reminds me of the torquey Spitfire Mk XIV vs the Mk VIII favorite.

its nicce effort of kawasaki caompani this company givs tha mechnical technologi a new horizon of envention i like its technology i m from paksitan as tha every one man know tha pakistan is devolped contry and there we used kawasaki technology but there is no your industriy i wana worke in your high level industry with your brilent engineer

Ron,
I used to believe a radial engine aircraft improved roll also. But then there seemed like there was one exception to the rule .......P-36/P-40. At speed the P-40's roll continued to increase where the P-36's fell off. Aircraft design is the key. Lord, I would really like to see some
test figures on actual roll rates of the Ki.100. From what I have read to date, roll rate, acceleration and high altitude performance are what set this Kawasaki apart from the other Japanese fighters.

Leo,
Mostly tuning. The Ha-40 and 140 were lighter than their German cousins which had tight tolerances and these lighter versions had even more precise tolerances still. So factory worker skill was at a premium.
Another thing is the quality of the fuel in the field.
Also there is the experience of the Japanese mechanics on inline motors vs German experience.
If tuning wasn't right, it could suddenly lose power.

The ki.100 was a nasty suprise to the us. It was an awsome plane in its own right but the King and Queen of the Pacific were the F4U-4 and P-38L. Go check out there real limitations that I have discussed on this sight.

In mock dogfights between equally skilled Japanese pilots pitting the Ki 100 Goshikisen against the Ki 84 Hayate, the Ki 100 always won. Every time! Hard to see how unless you witnessed it. The Ki 84 had the level speed advantage but it was over 40 mph slower in dive speed. Granted, the Hayate could outperform the latest U.S. fighters at medium altitudes and even out-turn the Spitfire. But the radial Tony was no Spitfire. It was somehow a superior adversary (except way up high). Add to that the fact that it had a tougher hide to absorb combat damage and was more reliably powered than the Nakajima uber fighter, perhaps the Kawasaki pilot's enthusiasm can be better appreciated. Inline Tonys have been said to out-roll (at least to the left) the U.S. Navy fighters, so maybe the radial improves roll, it should (ala Fw 190A radial vs Fw 190D inline). The right turn in the earlier Ki 61 Tony was much inferior to the left turn, maybe the Ki 100's radial helped with this flaw too. What's left? All we know for sure is the weight of the vulnerable liquid cooling required for the inline engine wasn't missed. Now it was lighter on it's feet.

If it came out of a high speed dive it was fast. The Kawasakis were the only Japanese fighters that could hope to dive with the Mustangs. Otherwise it's true that level speed was inferior to it's fore-bear, the Ki 61-II Tony (if it was well tuned). But the Ki 100 Tony dropped the weight of the liquid cooling on the inline engine, improving it's handling. The less vulnerable radial was more reliable than other late model Japanese radial fighters like the Jack, George, and Frank. Also much sturdier than the Tojo or slower late model Oscar and Zero. At a time when Japan's young fliers had abbreviated training, such a more simple 'pilot's plane' was made to order. It proved itself a success against U.S. raiders (especially the Hellcat) out of all proportion to it's numbers at the end of the war. Maybe best isn't the word. Surprisingly effective might be the right phrase. On paper it doesn't shine, but in the air is where it counts.