Only great downside, there must be a fix to people hacking game rooms. Like perhaps setting up a vote count to kick and 2/3 (or depending on number of ppl) must say yes for person to be kicked.
Other suggestions:
Don't make experience count as score points in battles, makes it unfair as the most inexperienced cant get his get 1st in a deathmatch because some lvl 1 shotgunner has an exp boost.
Also, can there be game mode where the maps or the match type shuffle? Anything customizable. (Or perhaps going above and beyond in allowing people to create and host their own games; I realize there may be downsides to that)