Just left a match where a reaper was over 300 points in the first 3 minutes when no one else had 50...and I wanted to say that this kind of situation still needs to be addressed, or the game may suffer (remember that the player base had shrunk to a few groups of highly skilled/perhaps sometimes enhanced players that were clearly playing on an elevated level that the average player [e.g., me and many new players] did not stand a chance to find some fun in.) This game has two strong selling points - best movement algorithm I've ever used, and when sorted and filtered properly, the best game-balanced, live matches going. Not there yet, and this last game worried me that such radical and obvious skill differences (real or enhanced) still negatively impact the game experience; it certainly does for me. I'm just a journeyman and expect to die a lot, but I'm also a player with thousands of hours of Hawken play, and if it acts like a duck and shoots like a duck then it just might not be an unaided-human-mech after all. The honor system did not usually work in the last incarnation (indeed once I was challenged with "everyone hacks dude, *** off"), and no reason to assume it will suddenly reverse.
I hope that keeping the playing field as level as possible will continue to be the highest priority. The other aspects of the game have all received improvements including this new system of challenges, which is a very cool idea. I'm all-in on keeping it fair and level and fun.
Perhaps this should be rolled into the conversation about re-balancing ongoing matches, where the incoming player is usually going on the losing side, where multiple leaves make re-balancing hard, or in-coming groups, etc., all shake the balance.
With all this focus on MMR, to me a ranking system cries out for a handicapping system somewhat like golf, where Joe Average can beat the pro on any given day. A 'handicap' could take so many forms, I'll leave it alone. It would be easy to test for an evening to simply see what happens. Anyway, overall the many changes you've made both obvious and subtle have been impressive, please keep an eye out for obvious departures from the curve; in large groups, most all behaviors are predictable, so the unsual/unexpected is easy to spot. Best of luck.