Erg and the rest missed a major point in this conversation regarding the whole "10 minutes over England for 109s thing".
In WWII pilots would launch, climb to 20,000' plus, get into formation, hook up with other squadrons, then fly over England!
CT pilots, on the other hand, launch, immediately turn on course to the furball at 50' altitude, punch WEP, climb to maybe 3,000' and arrive over England within 5 minutes of takeoff.
The whole realism thing isn't about the fuel burn rate it is about how everyone flies. The extreme enemy territory loiter times are because of this one fact.
If we all flew in a more reasonable fashion no one would be complaining.
I like flying 109s and 190s but I also rarely fly straight into the furball. More likely scenario as follows.
Launch with 75% or 100% fuel from second echelon base. Climb to 15,000' - 20,000'. At this point I've burned off about 25% of my fuel. Depending on bogey dope maintain my alt or put myself slight nose down and turn to target. Arrive at fight at about 50% fuel with major E advantage. Blow E advantage bailing out first friendly I see in trouble get low on E and get my butt shot off. Repeat.
Fly sorties as described above and you won't have more than 10 minutes of loiter. Increase the fuel burn rate to the point where I have to start flying like the rest of you and I'll be the one who is ticked off.