First time in a perk plane. Spent a lot of time tooling around just trying to find a fight, and ended up furballing low and slow over a friendly base that was being swarmed with enemies; got a kill and a prox kill when an enemy augered trying to evade me. Would have had two more kills except I'm not used to how the -4 flies--the departure behavior is a lot different than the Mustang

Twice I had lead and spoiled my own shot just because it "feels" different from the Stang--some time testing it out offline first may have helped a lot

Ended up losing my perk points, but not because of anything the enemy did--I ground-looped the F4U landing and it slid off the runway. F4U's are hard enough to land to begin with, and with a framerate less than 10 (lots of smoke and stuff around) it was a lost cause. Doesn't bother me any--I took off figuring I'd lose the points.
One thing I noticed is, contrary to the standard whines I see on this BB, I was not attacked any more or less than normal. Perhaps this is due to the fact that I tend to fly on my own (hence I am always being attacked), but I suspect there's more to it--the "icon whiners" THINK they'll get picked out of the crowd, and so when something attacks 'em they assume it's because of the ICON. I certainly didn't have any special trouble, and I spent most of my flight low and slow under a bunch of enemies.
As for performance, I feel the -4 is worth the price. It has tons of ammo, superb overall performance, and is tough too. It has no real weaknesses.
J_A_B