I'm no expert in it, but in my initial flying of it, I think it might be competitive with the 109F up to about 12k. It's a little faster than the F non-WEP, slower than the F with WEP, and it seems to roll extremely well in some speed ranges. If it turns as well or a little better than the F (which it might -- it feels like a very nimble plane), I think it would do just fine in Eastern Front matchups.
In the scenario "Red Storm / Krupp Steel", I flew La-5's vs. 109K's, 190D's, and some 109G's. There were fears going into the scenario that La-5's (indeed, even the La-7's and Yaks) would be highly outclassed by the late-war German planes. They were much faster and better at higher alts, but once the fight devolved into twisty dogfights down low (which is where they always ended up, because we weren't escorting high-alt bombers), we did just fine.
P-39's aren't as good as 109F's, but they aren't horrible below about 12k vs. 109F's. P-40's vs. 109's? Not as good.