Agree with future predictions. They are pretty pointless. You can go with the info you have now, but it will probably change.
MDW is and always has been a large base with a good variety of flying. Having talked at length with Spirit pilots I will tell you that the two scheduling systems are both very different, but both have the ability to really shape your schedule and/or pay situation. At Spirit it is easier to get days straight dropped. Once you get to know the system and contract at SWA, though, you can really utilize it to boost your QOL and pay.