With the large planeset available, ENY discussions should not even be happening. You like the La7, eny wont allow it fly the La5FN, you like spits, and the 16 not available, fly the 8, 8 not available fly the 9. You like ponys and the D not available, fly the B. Like someone said earlier, I don't believe the differences between models within each type is that significant overall. If living or dying or getting kills is dependant on you flying the late war models, then you "should" be flying earlier marks to improve your self.
My 2cents