I fired Delta as my carrier of choice years ago for several reasons (tired of making connections to go anywhere at all, frequent flyer program dumbed down to be like the rest of them, and...). The biggest problem with Delta is that their seat pitch in coach is only marginally better than the charter airlines of the 1960s and 1970s. I often could not reach down to put my briefcase under the seat in front of me or get it out later; I had to do it from the side. If you're taller than 5-foot-2, E+ would be a good reason to stay with UA.