for the first 40 miles off of mdw west bound the problem is we must miss the ord south depts and the ord arrivals from the south west fix, that means at times we have to do some vectoring to get the a/c climbed. if not you could be stuck at 4000 for 25 to 30 miles.it all depend on the config at ord and were the other a/c are, sometimes we can climb right away other times we cant, pluse it depends on a/c preformance we have to get you at 12000 ft to miss the ORD arrival traffic at 11000ft so we tend to vector a/c between the 10 mile gaps that the center is providing which takes a few vectors, as for what happens when you get to chicago centers airspace they have to blend the MDW/ south sat west track with the 2 ord west dept tracks, so depending on you fix they may need to do some criss crossing in their airspace.