I do a lot of medium haul flying on DL and therefore ride in a lot of MD-88's. I have found this bird to be no worse that others. It is a heck of a lot more comfortable (especially in coach) than DL's 737's.

Of their current fleet, I have experienced the most mechanical problems with 757's. The only emergency landing I've ever been on was on one of their elderly L-1011's whcih had a landing gear "issue".