Comparing the F6F vs the F4U:
Low speed turn: Slight edge to the F6F, however it's slight enough as to be largely insignificant. The difference is the F4U has the smaller turning circle full flaps, but the F6F a higher turn rate.
Speed: The F4Us have the edge at all altitudes, from slight (F4U-1C/D) to "Eat my dust" (F4U-4).
Vertical performance depends on the Hog. The F4U-1 is notably underpowered in the vertical, and while the A/C/D aren't stellar, they'll generally match up well. As always, the -4 blows the F6F away.
The same holds true for acceleration. The F4U-1's sluggishness is notable, however the A/C/D are more evenly matched. The F6F is toast if it tries to out-drag the -4.
At high speeds the F4Us have the advantage. The Corsair's rate of roll and high-speed turning capability is superior (again, the degree depends on the model). I believe she can also get her flaps out at higher airspeeds, (first notch at 250mph) and as noted in MANY threads, Der Uberflappen are among the best in the game.
Fixed firepower is equivilant, excluding the cannon-armed Charlie. For ground-attack, the F6F carries a heavier load than the 1 and 1A, however the 1Cs cannon help offset the extra pair of rockets on the F6F. The 1D and 4 out-haul the Hellcat slightly, with an extra pair of rockets (the difference would be MORE notable if we had the center pylon w/2000lb bomb + wing pylon 1000lbers + HVARs option on the 1D).
Durability is a tougher question. There's some people (myself included) that believe the F4U has been incorrectly made of glass in some areas (depending on who you ask it's the engine, outer-half of the wing, and rear fuselage). However both generally take a good heavy burst of .50cal to bring down, and can take a couple 20mm shells and keep flying.
The main advantage the F6F has is, as noted, it's more forgiving for newer pilots. Being able to really handle the Corsair slow takes a hot stick, and is more vulnerable in large fights if she's out of speed. Both planes match up very well in a number of areas are are very similar in performance, (which is why the F6F makes such a good bird to learn on if you want to fly the Hog) but assuming equal pilots the edge ultimately goes to the F4U.