Hopefully this isn't in the wrong forum, but what does the addition of XP and levels add to the Insurgency experience? I don't think it adds anything. For the last few days, I've gone back and played Insurgency (Source). That game had no experience or leveling mechanics, but that in no way detracted from what makes Insurgency (Source) a great game.
In Sandstorm, a match earns you XP which, each time you accumulate 20,000 of them, convert to either $100 or $200 coins. Levels are, effectively, just an indicator of how many times your XP have been converted to coins. Apart from that, levels really don't serve any purpose. The game would be just fine without them--their absence in no way lessens the awesomeness that is Insurgency.
This is not really a plea to remove levels, just pointing out that they really don't add anything to the game. In fact, they seem kind of pointless. Something to keep in mind for the next iteration of Insurgency (and I hope there are many--Insurgency and Sandstorm are great games!).