F4U-4 is by far the monster of the Hogs, however that comes at a well-deserved cost in perks.
For non-perked Corsairs your best bet is the F4U-1A. She turns BETTER than the -1, is slightly faster, and the range is roughly the same (there's some complaints about fuel distribution in the 1A, however I actually find it gives her more options than the distribution in the -1). Her acceleration and rate of climb is about equivalent to the 1D, though just SLIGHTLY better.
The F6F doesn't really have a whole lot of clear advantages over the F4U. The Corsairs will outrun, out-accelerate and out-climb the Cat, and will generally take more punishment before going down. Control response in the Corsair is superior at higher airspeeds (the Hogs will roll as well as virtually any aircraft in the game above 350mph) and both aircraft are similar enough in turning capability as to be negligible (F4U has the tighter radius, though the F6F is SLIGHTLY faster in turn rate). The 1, 1A, 1D and 4 all carry the same armament as the F6F (50 fewer rounds in the 1 and 1A, tho) and the F4U-1D has a heavier ordinance load (as does the -4, but I wouldn't want to waste that perk beast playing wrecking ball). And of course, the 1C has cannon.
The F6F IS more forgiving to fly, however, so would be a better mount to learn the game on to avoid the stigma of Spit Dweeb. I've been in the game over a year all but exclusively in F4Us and I still spin out occasionally at low speeds. Visibility in the F6F is also generally better, especially over the nose (high-deflection shooting in the F4Us can be a pain, especially in the -1).
However as an overall air-to-air combatant, the F4U (especially the 1A ) is superior, though not by a significant margin. The F4U-4 widens the performance gap between the Cat and the Hog quite significantly.