The 320/319 fleet flies everywhere in the lower 48, along with some Caribbean and Mexico. (there are even some European Charters for this next month for the NBA I believe, with stops in Iceland) Each 320 base has a mix of day trips, all the way up to 5 day trips worth close to 30 hours. In one 320 trip you may hit every base (MSP, DTW, LAX, MEM, SLC, NYC, ATL, CVG), and there are transcons too like TPA to LAX. The MSP MD90 category flies some ATL MD88 stuff, but also does one stops across the country in MSP mainly. You may start off a 4 day trip on the MD90 going MSP to San Jose, CA with a layover. The next day you go to DCA via MSP. The next day you fly to Bozeman, MT via MSP. And the last day you fly back to MSP, and then to Spokane and back to MSP and you are done. The 320 fleet has a lot of variety, but the MSP MD90 also has good trips, and 18 more MD90s are on the way too, slowly replacing some of the DC9s. The MD90s will eventually be flown at all bases, but right now MSP, CVG, and SLC are the only ones flying them, with NYC getting it next, and ATL last. Either way, both fleets offer some great trips. Some guys love the 320 so much they stay on it for as long as possible, and then go onto the A330. (a bigger 320) They like to say "DELTA" stands for "Don't Ever Leave The Airbus." Good luck!