I'm also deciding between these two. I don't have the impression that either one is more quantitative than the other; if you look at their curricula you'll see that their course offerings appear to be very similar. Also, keep in mind that all of the DC universities are part of the Washington Consortium, which means you can cross-register in classes at any of the universities if you find something that appeals to you. I've found employment reports here and here. Again, pretty similar.
For me, this means that more minor factors are important, like lay prestige, etc. GW, of course, has a bit more of that. I also like that TSPPPA is solely for graduate students, whereas SPA is also an undergraduate school. There's also the Google group that GW has provided, which has made it very easy to communicate with current students and ask questions. I just feel like I've had access to much more information from GW, and that appeals to me. I'm still going to try to go to the admitted student events for both, though.