I think it matters. Wasn't one of the reasons MySpace lost vs Facebook the fact that users could edit their page to look like a vomit smoothie on MySpace but things were kept clean and uniform on Facebook?

Regardless I think it matters. There have been a few threads on here about how developers can't design for crap, and engineer developed sites look ugly. So I give up. I'm going to finish coding my project, then pay some design firm to make my ugly baby pretty and launch.