One interesting thing about the Ki-44 is during the annual Evaluation of fighters, the Japanese Navy/Army put the Zero up against the Ki-44, the Army boosted it was a far better fighter plane. After the disaster of a show for the army, they tried everything to increase performance and such. Top Speed was only 389mph however all tests were done without armament etc. Early 44's were armed with a pair of 7.7 and 12.7mm machine guns.
Pilots were not happy with the lack of manoeuverability and high speed landings, it was troublesome for veteran pilots and like the corsair - deadly to green pilots
It was tested in fights against the 109E/2 and Curtiss P40-E in which the SHoki did outstanding.
Its interesting to note - The Ki.44 would of done great intercepting B17s and B24s over Japan, however with the arrival of the B-29 it was simply outmatched.