Possi,
Well, the Bf109 may have had 5 times the roll rate of a P-51D, but its funny how that has never been mentioned by any of the pilots of either aircraft.
HiTech has flown a P-51D, IIRC, and and thus the P-51D flight model in AH is almost certainly close to the real one.
As to the P-39, I'm sorry, but modern combat jet fighters roll slower than that. Unboosted, non-fly-by-wire aircraft simply shouldn't roll faster than the best modern combat aircraft.
BTW, I wouldn't put too much stock in the fact that Bf109 pilots have given their input. 'Bud' Anderson gave his input for WWII Fighters, and look what a joke that FM is. There was a NovaLogic "sim", F-16 vs. MiG-29 I think, in which they got test pilots from both manufacturers to assist. The Russian guy had very scathing things to say about how they took the input. The American guy said of the final thing that the USAF and Russian Air Force wished they had aircraft that performed that good. My point is that having actual pilots involved is frequently more of a marketing ploy than an attempt to make the FM more accurate. I know Oleg has poured a lot of effort into this, and it really shows, but please, look at it with a skeptics eyes. Don't assume that it is absolutely correct.
Thanks.