While the F6F did hold a higher kill/death ratio than the F4U, it was not it's sucessor. If the F4U were cleared for carrier operations sooner, it would have seen more action and gotten more kills. The Hellcat and Bearcat were obsoleted by the F4U variants, as such the F4U was able to fulfill the future roles better than those planes.
I haven't looked up the data, but I have a very hard time believing the F6F (and F8F) were as fast or faster than the F4U. The F4U had a lower drag airframe with the gull wing configuration and extensive drag reduction was done by the NACA before ww2. The F4U saw much more service after some operational issues were worked out than any F6F or F8F variants and was used long after the introduction of jets into the early 1970's.
I would be interested to read in reports why the Navy phased out the F6F (or F8F) and kept the F4U for 40 years. Jets played a part in that decision for sure, but whether it was range, durability, ordinance capability, or maintainablity that edged out the F4U from its simliar era planes is a mystery to me. On the topic of speed again, how many F6F (F8F) planes were used in civilian racing? None that I have ever seen, but the F4U (and P51) were top contenders.
Regards,
Malta
p.s. talking about the game now: if the F4U-4 had 4 20mm hispando's, then it might be one of the 'best plane in the game' and worthy of the perks. Above 250 ias, the P51, 109, 190, and La7 are more maneuverable in the game. Many planes in the game are more manueverable below 200 ias (including the F6F). One could say it has a combination of attributes that make their sum greater than the parts, but I would not after flying it. Marginally better acceleration and a slighty higher top speed than the -1C with inferior 50 cal guns doesn't count for much in a fight.