BWI, MDW - great. Easily available, cheap, good transportation.
MCO - not a traditional commuter base but plenty of cheap hotels. I am sure there are one or two crash pads there, but I have never heard of them.
OAK - avoid at all costs. Zero crashpads, hotels are either expensive, $hitty, or both.
The good thing about swa is that you won't need THAT many hotels on reserve. You will mostly fly. The bad thing is that commutable trips are few and far between so you will need a place to stay unless you fly PMs and don't mind hanging in the lounge with the sleep apnea demo team.