Oh, and how does the P-38 or P-47 (two of the most widely used US fighters in the ETO in 1943-44) stack up so much better than a Corsair? or even a P-51B for that matter? It can hold its own if compared to any of them, each a/c of course hase particular strengths, and weaknesses, as they always do.
I will also add the Germans never test flew a Corsair, because they did not ever fight it, so I would wonder what "evaluation" they supposedly gave it (even if they had one) was based on. The only time the Corsair was used in Europe was the Royal Navy/RAF Tirpitz raids in 1944 in Norway, and the air combat was minimal. The Germans knew very little about the type past what the Japanese could tell them, and they were certainly not dismissive about the a/c capabilities.
I could see the F4F-4 Wildcat not being suitable for ETO ops in 1942-3, because it lacked the performance. Thats another story.