For the sake of clarification, as I have no opinion about its inclusion into the setup:
Anybody that's flown it knows it's a damn sight better than the P-40B, turns not as tightly as the spit or hurr1, but almost, and dives much better, but those 6x50cal are much more powerful than anything the allis or axis have. That's about as much punch as the 110c has, but with more consistent results.
Even 2x 50cal are better than 4x .303cal. I think HT models them at as 1 50cal is 3x as powerful as 1 .303cal, but that's just round power. That's not counting ballistics, armor penetration, and effective RANGE of the gun.
4x 50cal would dominate the setup if they were included. 6x50cal would overpower it.
On the one hand I can see it being used as a historical foe for the zero. The 4x50cal version WAS around during this time.
On the other hand, it would be like adding the P-40E. Doesn't matter if it has less AMMO than a P-51 or F4u, it still has the same punch as they do. You get less bursts than the other late war planes, but the effect of any single burst is usually the same: Massive damage [EDIT: Unless you got rubber bullets -- another issue entirely]
With 7mm birds, 600 is "safe" range. With a 50cal bird, you're in the kill zone. It changes gameplay and how the fights take place.
Whether or not it's included, either way suits me. I'd personally shoot at it or from it equally. It's also a tough plane that could probably take most of the ammo a A6M2 or 109E has to offer without going down.
Since forever the over-engined FM2 has been used as a Brewster replacement. I've been against it since forever because the FM2 flies circles around the Brewster. However, the only other option is the F4F-4, and since forever, folks have been saying that the added firepower of the 6 guns makes too much of a difference to use it as a substitute.
I'm not saying use the FM-2. I'm just saying that since "forever" folks have realized and admited that the added guns on the F4F-4 make it a more powerful killer.
P.S. The current allied rides (not counting F4F-4) are perfectly capable of killing the axis rides. Once bombers show up, added firepower will be needed, but not now.
[EDIT: I mean the FM2 is over-engined to be a Brewstersub, compared to the 229 it's overpowered]