I believe that when you give people the ability to control the look of the site, the result is almost always a horrible one, and does nothing to help the quality of your site. I should also mention that Myspace had long lost to Facebook when they began overhauling their site to where it is now.

I don't believe profile customization is a feature people would use as a deciding factor (or much of a plus) for when joining a site (or maybe they would, because it kept me away from a few when they were see more the popular thing to do in the previous decade). I haven't heard many people complaining about the lack of customization options on Facebook and other sites. I don't think people really care, as it's not the primary reason for joining such sites.

I agree with the agreement of disagreement (and another twenty circles or so of this). If you want to allow such features on your site, it's your choice, and you should ultimately be basing your decisions on what your members want (to an extent, of course). You can cater to the kids with mohawks and pants which hang against their waist line.

I'll focus on a consistent design and the overall experience which keeps people coming back.

Pretzel.