Those were two of my favorite planes to fly. The nik when it was young in this game and the Ki-84 from 07 to 09 when i left.
The Ki-84 is an all around great plane.
Fast...compresses about 400 mph but can reach about 425-30 before parts are gone
Maneuverable
Fairly good gun package but could use a few more cannon and locate them in the nose like the Ki-61's were would be best
Flaps work great but you need to be moving under 200 if I remember correctly
Climbs pretty good, can keep up with the P-38 pretty well...in fact >>>
A helluva P-38 killer....I've pizzed some of the best off