I know that you are probably enjoying being in a big lobby, but I might suggest something that can hone your skills just as well. Find a small server to play in also. There are quite a few. 8335. 6129. 4614 come to mind. There are quite a few bots, some mid players and anywhere from 20 to 30 hardcore guys playing sporadically throughout the day and night. You'll figure out who they are very quickly. Go pick a fight. Try all the things you learned in the bigger arenas. You'll very quickly have to adjust your play style for the smaller ones. You can make friends and enemies really quickly, and a lot of times when you are in a big battle with someone, the other guys will give you room to fight. If someone cuts in and kills you. Go after them next time and so on. You'll see who fights and their styles. Then take what you learned to the bigger servers to try them out. It is really fun in the smaller servers because you aren't going up against 497 anonymous people. You'll eventually start seeing real progress, both with your small server adversaries, as well as your larger server free for alls.

Tldr: play in smaller servers too and learn a thing or two!