Although a great experience, it's difficult to judge wartime performance on a preserved machine. Sensibly, owners will limit g and other stresses on the aircraft (such a power settings) to preserve fatigue life and maximise TBO. The P51 pulled enough g in wartime configuration to warrant a g-suit; many Mustang aces attribute the extra g they were able to sustain (and the K14 gunsight) as the reason they were successful. Mind you, the virtual cannon-fodder that the Luftwaffe were putting up in early 1945 probably helped....