Midway is okay now, but it will be better when the new gates are also open. The new Midway terminal is in use, but the departure/arrival gates will not be open until September. As a result, it is a long walk from the terminal to the old gates. In fact, it may be as long a walk as the walk from the terminal to the gate for United flights out of the C concourse at O'Hare. Worse, the baggage service for checked luggage takes a long time because the planes are so far from the terminal and its new lower level baggage claim area. However, once the new gates are open as well, the walks will be shorter and I hope the baggage service is quicker. We've waited 30-40 minutes for our luggage the last two trips, both on ATA, coming in from Las Vegas and Orlando.
On the plus side, the long-term parking at Midway is more convenient than at O'Hare. There are three lots (yellow, red, and blue) just a 5- to 10-minute shuttle ride from the terminal. The yellow lot is closest, with the red and blue lots being equidistant and a little further away. Long term parking cost is $9 per day, a bargain in Chicagoland, although I seem to remember it being only $6 per day before they built the new terminal.
From our location in the western suburbs, it takes about equal time to drive to either Midway or O'Hare. Flying to Orlando is usually cheaper and more convenient via ATA out of Midway. ATA runs four flights each way nonstop to MCO. Also, ATA does not require a Saturday stayover to qualify for their best fares. I just booked an early January trip at $180/person RT.
An interesting note on those new 757s that ATA is flying. Only some gates at the old terminal can accommodate these larger planes. When we came in from Las Vegas, our flight arrived about 5 minutes early (after being held at departure for an extra 15 minutes because of anticipated favorable tail winds heading from west to east). We then had to wait about 30 minutes before a gate was available to unload because the only two ATA gates which could hold this plane were still loading. I hope this problem disappears with the new gates as well. Midway has an interesting layout. It is a square parcel, 1 mile on each side. The 4 main runways are oriented as two parallel pairs along the diagonals of the square. There is a 6522 foot alongside a 5142 foot runway along one diagonal and a 6446 foot alongside a 5509 foot runway along the other. I haven't been overly concerned about landing in these 757s on these runways, but I haven't had any experience on a flight landing in bad weather. You certainly do feel the deceleration when the brakes are applied.
All in all, we've had okay experiences with ATA out of Midway and will continue to use them. They are certainly in an expansion mode with plans to add 1500 employees to Midway and double fleet size over the next 5 year.
Ralph