It's got a huge city for you to explore, but compared with the deftly filtered visual richness of something like Grand Theft Auto IV (a comparison that's going to be hauled out a lot, I'm afraid), it looks dated.
You could talk, in technical terms and a tone reminiscent of a slightly disappointed maths teacher, about how the graphics aren't terribly impressive. If you want to talk about Saints Row 2 (right place to be, innit), you've got two different approaches open to you.