Just for interest, did some testing last night.
P-47D-40 with 75% fuel and the 8 gun 267 RPG package-14,007 lbs, 28minutes@ mil power.
P-47N with 50% fuel and ditto-14,650 lbs, 28minutes@ mil power.
Climbrate (Auto, right off the runway, noted it as soon as it settled)
D-40, Mil-2,500 fpm
N, Mil-2,200 fpm.
D-40, WEP-3,100 FPM
N, WEP-3,200 FPM.
Conclusions:
I have no way to test turn radius, but I suspect the larger wing on the N probably cancels any advantage the D-40 has in turn from its lighter weight.
IMO, for MA use, the slight speed and climb rate advantage of the D-40 on MIL is not as as beneficial as being able to go 20+mph faster on the deck than that horde of Spits behind you looking for an easy kill.