the G modelling seems ok to me but some people seem to think your heads going to explode if you pull -2G for 2 seconds.
do you know long a trained fighter pilot can withstand sustained 3G, 6G, 9G, 12G, 15G etc? and exactly how many Gs and for exactly how long you're pulling them during a fight? someone posted the numbers here, search for them you'll be surprised.