Something else to consider is private tutoring. Yes, the time you spend in front of an instructor is less, but you will get more out of each hour.

To answer your question, though, I think M GMAT has a better curriculum (although it is important to note that Kaplan now owns M GMAT)

Not to turn this into a pure marketing thread, but since the topic said Chicago I had to look. Two Veritas Prep Worldwide Instructor of the Year winners (Frankie and Kevin) teach for us in Chicago and I've always been particularly proud of our team there (I'm a Midwesterner so that matters to me and several of our headquarters staffers went to Kellogg or University of Chicago so we spend a lot of time thinking about Chicago). If you're interested in checking out a free lesson to see what you think, let us know!