Just anecdotally, I figure DL must have outstanding performance because it is always my carrier of choice, yet this year I am up to 58K MQM on United for all the flights I took where I could not afford to fly Delta. These were all routes where Delta had the published fares I wanted but itineraries where all I could book were fare classes like M, H, Q when UA was still wide open on the comparable route at much lower fare bucket levels. I've already passed DM for 2014 but I realize I have lost a ton of rollover and hope that I don't lose status in 2015 if I can't obtain reasonable fares on DL. In 2011, 2012, I was averaging about 26K on UA to compensate for unaffordable DL fares and that has more than doubled in 2013 with more UA/US flights booked later this month. I'll feel really bad if I make Platinum on UA by the end of the year because those are all trips I rather would have taken on DL.