Personally the jury is still out on the new ENY system. The system does not generally affect my choice on plane since I fly the F6F most the time, while occasionally dabbling in the rest of the planeset.
Here's a potential issue... and I say potential because I don't think the new system has been in place long enough to see any general trends in gameplay this is merely a (potentially unfounded) concern of mine.
For someone flying for the outnumbered country and I know my opponents do not have access to La7's, P-51's, etc... that is exactly what will be flown more often. Because there would be the realization that the country with the most people won't have anything that can chase them down. Result is more "timid" flying more running and a very bored Soulyss trying to catch them in his clunker of a F6F. I will admit that I'm pretty much a furballer at heart. I don't really care about winning the war, score, or anything else. If I can log on find a good aerial battle I log off at the end of the night content and happy. Chasing P-51's and La7's all night does not fit that criteria. Which seems like I've been doing more and more last couple nights. I dunno if it's coincidence... sometimes you have good nights sometimes bad and it's too early as I mentioned to pin it all on the new ENY system. But the concern is definetly lingering int he back of my head.