Excellent Badboy, thanks.
I did some testing of these when the Beta debuted. I concentrated on full flap turn radius and rate.
Speed @ SL 50% fuel
B-239: 280 mph
I-16: 275 mph
A6M2: 270 mph
Hurri I: 262 mph
Turn radius and rate, full flaps, 25% fuel
B-239: 329 feet @ 22.5 degrees/sec
I-16: 382 feet @ 21.8 degrees/sec
A6M2: 315 feet @ 25.1 degrees/sec
Hurri I: 364 feet @ 23.3 degrees/sec
I have also fought a few duels with the B-239 vs the A6M2.
We found that the Zero's better instantaneous turn rate will give it an edge on the initial reverse. However, the Brewster has more benign handling at the limit with flaps fully out. My opponent in the Zero was a very good 1v1 pilot, but he invariably ran into departure issues when both fighters were hanging on the edge and augered twice. The Zero would depart violently, whereas the Buffalo was easily more managed, with no tendency to snap into a spin as the Zero did. Historical? Not likely, but it is what it is, if you will..... The Buffalo's vertical behavior was remarkable as you could hang on the prop at very low speeds. Meanwhile, the Zero would lose aileron authority and rotate around its own flight axis while trying to follow. That would lead to a messy departure and the Brewster could capitalize on it.
Flaps up, the Zero is better. Flaps down, it's nearly a wash. In between, that's where pilot plane handling skill can make the difference.
Over all, the Brewster is surprising in being quite competitive with the A6M2, and superior to the Hurricane Mk.I. It is a real threat to all other early war types.
My regards,
Widewing