How does Tempest compare to F4U-4? I think this is more about the player than then plane. Could a good pilot beat the Tempest in question? 
The F4U4 lacks cannons which IMO is extremely important. This means it normally gets picked having to chase planes longer due to the 50s not downing planes quickly enough. The Temp has the overall best 20s in the game. One pass with a few bullets insta towers planes. It makes a hell of a difference to get the kill quickly rather than having to chase with 50s that take 100s of them it seems. Especially on Bombers.
The F4u4 will out turn it and out dive it, but can it out accelerate and catch it? Im not so sure. The F4u4 invites 1v1 fights more than Temps, which gets players picked in them easier.
The Tempest is much stronger in the attack position due to the cannons and body strength.
Theres a reason why more guys use the temp than the F4u4. I think its because they'd rather hit X and run, and always dictate the fight on their advantage and terms and mostly, be able to run from the gangers, which I do understand that to a point, but being in an advantage plane doesn't make it very fun for the other payers.