I always liked the looks of the plane, somewhat tubby yet with elegant lines. Its stats looks good for a Japanese mid-war fighter (here i'm thinking of the Ki-44 II), and fifty years ago I first read that it dived and climbed well. The armament of the early variants was nothing to brag about, but better than the Ki-43. I never heard about any issues with reliability, and it (again the -II) should be a match for the not so lucky Ki-61. But I've never encountered any solid information on actual achievements. reading Bloody Shambles i got the impression that it did little better than the Ki 43 over Burma, both the earliest model but also later in the war. With (from memory) 1225 produced, it should have had a chance of making a bigger impact than the 'parallel' J2M that did have reliability issues.
The comparison with the Ki-43 may not damn it as much as some may think. With time i have come to believe that this is underrated, though it certainly had its limitations and in no way had stellar performance. But one point where it decidedly IS underrated is where the zero early war got credit for many of its achievements, everything with a radial and a bubble canopy being identified as zeroes. And at least the models with 12.7 mil guns were better off armaments-wise than a zero that had expended its cannon ammunition, at least until the A6M5's got heavier machine guns. And the manouverability of the Ki-43 did not suffer as much as the zero at higher speeds. It does seem to have suffered somewhat from lighter construction though, but as Justin Pyke (appearing on both Drachinifel and Military aviation history youtube channels, it should be this one):
cited statistics from new Guinea where really confirmed kill rate between Ki-43 and Thunderbolts were around 2:1 in favour of the latter. Though from a small statistic sample, that surprized me. This was quite a digression, back to the Ki-44.
For the late war it was certainly falling behind the curve though avoiding the trouble connected with any plane using the Homare. But mid (pacific-)war it should not compare badly to P-40's and P-39's, or even the Hellcats while the early P-38 should not have too much of speed advantage. It may not, however, have been flown to its strengths, as Japanese army pilots seem to have clung more to dog-fighting (again according to Justin Pyke the Japanese navy over China and early Pasific war preferred power tactics). Later dog-fighting may have been the only area where the zero still had an edge. But to again compare the Ki 43 and 44, in late war the 44 may not have had much superior manouverability compared to allied fighters while it decidedly performed worse. That may have left the 43 the only one who had a clearly superior trait, even if it was extremely hard to capitalize on and the gulf in performance was even wider. Context is important, and I may easily overlook some important aspect.
Some here certainly shows the Ki-44 some respect, while others do not (somebody termed it 'mediocre' at one point), but I would be grateful to anybody who would take the time and trouble to give their reasoned opinion (together with hard facts they may have gathered) about this little fighter.
PS there's some info in this thread I dug up after writing the above, but that only sharpened my appetite:
Another question that's been in my mind for a while: You always hear about how the Ki-44 was a "fast climbing, speedy interceptor" but "was disliked by most of it's pilots for its lack of maneuverability and turning ability". How accurate is that description? Is the Ki-44 really that bad, or...