How about in independent view (neither dedicated LW and tiffie specialist):
1st Round planes were even, LW advantage slightly with faster A5's and climbing G2s.
2nd Allied planes started to pull ahead. P51Bs, Tiffies, F6s, F4s, LA5s, Yaks, better Jugs.
3rd Round was completely off the scale. In our sector we had at least 3, maybe more, Tempests.
I would have to say LW things were fairly disorganised. 60% of the pilots in my cage didn't turn up. I was in desperate need of macro's.
All in all a pretty good simulation of the late war LW, newbie pilots, crap planes, bad organisation

Next I'd suggest a more simple planeset, the first round was the most closely matched IMHO. And given the Allies did win the first round I think this gives them the definite victory - balanced or unbalanced in the later rounds.