http://www.wallstreetoasis.com/forums/booth-vs-hws
Booth is incredibly strong on the quantitative front. Our MD had an MBA from Harvard, but he would get nervous when a Chicago or Stanford guy would start talking about anything more complicated than addition or subtraction. Chicago guys are known for having a disciplined and somewhat numerical approach to stuff.
I guess the real question is what do you need to complement your background? If you have a liberal arts undergrad and IBD or Sales background and want to move into something like research or asset management, I'd strongly recommend Chicago or perhaps Wharton. If you have an engineering undergrad, quant trading professional work, and want to go into consulting in some Northeastern city, Harvard is probably the better choice.
Chicago and Northwestern are a little less selective than Harvard, Penn, Wharton, Yale, and Stanford but they still manage to have the same reputation among hiring managers- and they manage to kick Stanford's, Yale's, and Wharton's butt. This should tell you something about the overall value and quality of the programs. I also think this is where you start seeing the self-selection of cultures for the schools. If you want to signal that you're exclusive, that's Harvard. If you want to realize your potential, though, you're really looking at Booth or Kellogg. Booth is the more quantitative program; Kellogg is more soft-skills.