I like to fly the p40e. Its a good, stable gun platform and is very nice for perk farming. Depending on the alt of the fight, I like to take it into furballs somewhere between 8-12k. Its only positive attribute is that its a good diver, so with enough speed it can pounce on low, slow, unsuspecting enemies. However, if you have to do any sustained maneuvering to get a shot or evade an enemy, then you will bleed energy like a stuck pig and become lunch meat. engaging furballers and getting quick picks with friendlies covering my back is the only time I'm ever successful in a war hawk. 1v1, the opponent would have to really F up for you to have a chance because once he gets on your 6 theres almost nothing you can do. Getting a kill or two is normally not a problem, but surviving long enough to land 'em is. Lets face it, when a p40 makes an appearance in the MA every con out there is thinking, "hhhmmm shrimp on the barbie!".
The thing about the p40 is that...its a flying bicycle. As long as you keep your speed up, you can tango with anything as long as you don't play to their strengths because just about any given plane can out turn, out climb and out run a p40. Since its so slow, I would pair it up against something that is a real dog if it gets as slow as the war hawk