I play on a Clan Arena server using QLstats on a daily basis. The system works decently, but there is one HUGE flaw.
About 33% of games are ruined because teams are not well-balanced. The reason behind this is the new players' ratings are absurdly high.
Most new players play like they have more or less 800 elo. However, I can imagine setting the default elo to 800 would make it too difficult for new players to raise their rating, and it may also impoverish the balance of games in which good players with new accounts join.
My proposal is to lower the default rating of 1337 to 1000 as I believe this is a good compromise.