Well, I've noticed in Munk's admission offer that they really advertise student and faculty run extracurricular activities (be it crisis simulation, joining editorial boards, etc.) which does make the program attractive. The MGA program also seems more focused on career development, and there might be a bit of an advantage over NPSIA given that the internship program is mandatory and acts as a credit (helping you build a professional network and possibly even securing an exchange). While NPSIA offers numerous internships, you do have to apply - making it somewhat competitive. MGA Labs at Munk also seems pretty interesting and somewhat innovative for international affairs. Also, there are many opportunities for jobs given the size of Toronto and the number of NGO's, charities and non-profits around.
However, I caught up on this forum a bit and noticed that a few people had negative experiences visiting Munk, so what I'm seeing online may not be the reality of the program. There are only three specialization streams at Munk, which is kind of a downfall. NPSIA offers a lot more ($10000 difference) in terms of funding. Also, the MRP and Thesis options at NPSIA may be beneficial if one decides to apply for a Ph.D. Not to mention NPSIA's reputation, co-op programs and ties to the Canadian government.
A lot of other people mentioned the positives of NPSIA so no point for me to go on about them. Looks like I'm leaning towards NPSIA though.
Has anyone accepted NPSIA yet?