Originally posted by Kaz
Hi Nexx, Saint AW 
Arlo summed it up pretty well. So expanding on his comments and adding a few of my own:
Ki84 is great but you'll eat it for lunch in your Typh. It rolls well at medium speeds, not that bad a diver I think 500+ mph and things start falling off and the controls start to get heavy around 350mph. It climbs very well, stalls are gentle, can get the nose up and keep it up for guns solution at very low speeds.
I see Kaz hasn't figured out the Ki-84 yet. Since the patch, the roll rate rivals the 190, especially between 300 and 350 mph. sustained climb is excellent, but the angle of climb and rediculously low speeds it can maintain in the vertical are unmatched by anything else in the plane set. You can spiral climb to 12k at 120 mph and never go outside the base parimeter. Your controls get heavy at high speed because you are flying with Combat Trim on. Turn it off and trim manually. The ailerons don't get heavy at all, roll rate falls off as speeds exceed 400 mph, but it will still out-roll just about everything else except the 190s and P-38L (which is the fastest roller above 400 mph).
If the Ki-84 has any weaknesses, it's in acceleration and low level speed. Both are only average at best. But taken as a whole, the Hayate is one of the best all around packages in AH2.
IMO Typhoons will have a hard time mixing it up with Ki-84s. Better to stay fast and use those 4 hizookas snap-shooting. Nexx, treat Ki-84s like you would any fighter that climbs better than a Niki, rolls like a 190, turns like a SpitV and has the fire power of the Dora (shorter clip tho).
My regards,
Widewing