I knew several Buffalo pilots including USN, USMC, and RAAF. All of them liked it AS A FLYING MACHINE. No less an authority than Marion Carl said he would've done as well at Midway in an F2A v. his F4F. New Zealand's leading ace against Japan, Geoff Fisken, said he liked the Brewster for its .50 caliber armament and dive performance. (His previous ride was a Vickers Vildebeest, IIRC.
As noted in this thread, the F2A suffered from poor carrier suitability (weak landing gear), and VF-3 kept some aircraft off the flight schedule in order to have a few for an emergency.
With limited production, some parts and even aircraft were hand-fitted, as I recall from one or two USN guys.
Also as noted, the company was rotten with corruption (two managers went to prison) and incompetence. I do not think that any F3A Corsairs went to combat--retained for operational training.