The only P40 I have to judge it by is the one I flew in AW. That one was a dog in all except the dive.
I was surprised by the E retention of our new P40. It does hold it well but when it's gone, if you don't have some alt, you're gone too.

Fly it like an F4U. Come in with a bunch of E, don't deviate from your line alot, then get the hell out. Stick around, and you'll die.

Ah, yes, almost forgot. Excellent view forward for deflection shots.