Thanks.. this is great dialog and feedback.
In either case, we'd have rewrite rules to reformat the URI's into something internally useful.
Here's more info related to our thinking. Some of us believe that username.sonicswap.com is
much cooler than
www.sonicswap.com/username.
The belief is that there is more a feeling that users will feel more ownership and affinity to their contributions (aka playlists). We want to encourage users to have links to their playlists on their blogs, websites, etc. and if its cool they'll do it.
Some others of us believe
www.sonicswap.com/username is just as cool and without the drawbacks of the other approach.
The drawbacks we see of username.sonicswap.com is that sites (like this forum) don't automatically recognize it as a URI and won't covert it into an actual link like it will a
www.sonicswap/username link. The other drawback is that search engines treat each variation of username.sonicswap.com as a unique site which limits the optimization that can be achieved.
I suppose the bottom line argument to the two is if username.sonicswap.com is so much cooler will it offset the drawbacks it has.
I suppose its a matter of opinion too. It would be interesting to see what the experts have to say.