Hi, I'm so glad someone else on this forum applied to the MIPP at Laurier. I'm basically in the same boat as you except I'm trying to exclusively pick between Waterloo and Laurier so I can't really say about Queens. My passions pretty much apply to both private and public sector work so its more of a funding issue for me.
However, if you're looking for more private sector I would definitely say Laurier as the program boasts a connection with the CIGI think tank and seems to be more of a humanitarian focused program. I've looked at some of the researchers and it seems that a lot of their research could relate to private sector initiatives where as the co-op at Waterloo seems to be very public sector focused and driven. That's just my opinion and I'm sure either program could be very useful.