Well, Queens' is pretty much at the top for most of the criteria you could have when choosing a college.
Location; great because it's central. It's old and pretty (have you visited? The old side is split into lots of little old quads instead of one huge and austere one, it's much cosier), and is on the Cam so it has punts etc.
Academic; it varies from year to year but they were 5th on Tompkin's for something like 7 years running. Basically in terms of prestige, there's the elite colleges like St. John's and Trinity, and then there's a second band of old, well respected colleges, which Queens' is one of.
Social; it's a good size (medium to large) so you can get to know everybody but you're not restricted friendswise. It's also got a reputation as a 'nice' college. Their Ents are quite famous.
Robinson on the other hand is out of town, is overwhelmingly made of nasty
lego bricks, and kind of in the 'third band' with regards to prestige. I don't imagine it's that famous for social events either, although I'm sure the people there are just as nice.