F7F
F8F
P-51H
Seafury
Yak3U
La-9/11
Of these birds I would give the edge to the P-51H and possibly the Yak3U above 20k. We already know how the PonyD does above 20k. A lighter, faster bird with greater control surfaces should only do better. If the Yak3U performs like a cross of best aspects between a PonyD and Spit it should do well above 20K. Any indication the La-9/11 has anything above 10K, let alone 20K? The Seafury is a slimmed down Tempest. Maybe it has some skills above 20K though my guess is its primarily a below 10K hero, just a guess.
As for below 20K, my sense is the F8F is king of the hill. Incredible climb rate, rolls with the best, lighter and should out turn any of them. It is weak on fire power with only 4x.50cals but good enough in well trained hands. Maybe this is where the Yak3U and La-9/11 shine. With the PonyH, I have great confidence in its abilities below 20K. The PonyD is more then ample, can only imagine a more nimble version with much better climb rate.
Boo