I'm also interested in this topic as I'm considering moving from FLL to the greater DCA area. I fly 45 weeks out of the year, mostly domestic and Canada and have been very happy with DL in terms of schedules, price and most of all, complimentary upgrades out of almost every city EXCEPT DCA -- I never get those. So, thinking about DCA as my base is perplexing, especially if I'll rarely get upgraded, even as a PM.

My question -- what other airlines that basically do a good job of covering North America out of DCA have better complimentary upgrade chances once you reach the highest tier? Thanks in advance for any input.