I went through MDW twice this weekend. On Saturday I had the unfortunate experience of having to spend almost 4.5 hrs between flights.
The new terminal is very nice, spacious, and modern. Only the ticket check-in counters, rental car counters, and baggage claim are operating. There are no services, food or aircraft yet. It's quite a long walk from the gate to the baggage claim....I had to retrieve a bag checked on Southwest from STL and recheck it to MSP on Northwest. It was relatively painless.
Until the new terminal is fully operational, Chicago Midway is still the armpit of the U.S. I find it miserable to spend even 15 minutes there with the poor facilities and rude employees. Unfortunately, I was stuck there for a long time and Saturday with only a bartender in a bad mood serving me over-priced beer to keep me occupied. If you can avoid MDW (I couldn't this time), do so. Even if it means increasing your fare by $50 and going through ORD....it's worth it in my opinion! I can't wait until the old terminal becomes landfill.
A noble spirit embiggens the smallest man...