IMO the G effect is more against the Red planes than the Blue ones. Overall against Spitfires since you must be careful after the BnZ with those planes (because BnZ is not a Blue tactic, it's THE tactic).
And of course if you are damaged you can't turn hard anymore, a thing that usually average blue fighters don't do.
Anyway, in full onesty I want to respond to those who claim that Axis FM are ok since the blue pilots' online scores you: it's not the plane, it's the pilots... blue pilot must use tactics and be very skilled (trained) to be successful, while usually in red planes (not PTO) you don't need to use great tactics to score some kills... because of these IMO the average blue pilot is more skilled than a red pilot; I can say it because in many times I've fled as Red (I fly both sides to balance the mission) usually I don't find cooperation with Red pilots (pilots of my squad are witnesses too).
You know, "every idiot can fly a Spitfire"...
The times you use correct tactics and cooperate with your teammates (example 3 spits at 5km against multiple Antons) you win easily. And think about multiple P51 or P47 at high altitude, it's the nightmare of blue pilots... still today I find very few red pilot flying with correct tactics...
And at last all the 190s and partially the 109s in the stock IL2 are REALLY weird respect to the most of the other planes who are quite correct (the new Spitfire for example...). PM me if you want the reasons...
I have to admit that the P51's improvement really pisses me off... because P51 were used by pilots in the 190's way (but P51 being still better in everything except for the guns)... we tested now and they are improved, while 190s are still the flying bricks.