congrats on your acceptances to all of those places...from what i know they're all good schools.
a lot of where you end up going should depend on where you plan to work. i've spoken with some people at usc, and it seems for the mpa program, many students end up working the los angeles area. (this isn't to say that others don't find work elsewhere.) but also, usc has the "international labs" that might provide a nice opportunity to get non US consulting (?) experience. usc's sppd website is really helpful with these sorts of things. i think they also have an ambassador's program of the sort where you could talk with a student representative.
as for gtown and cmu, i'm not sure about those programs (sorry...).
i know it's not a ton of information, but i hope it helps?