ultimately it comes down to where you expect your music to be heard.

for myspace, it'd be understandable if you wanted to have a recording that was peaking as loud as possible, if you were going to be using your myspace page as a way of impressing promoters to get gigs or management, say. You might want to have as much immediate impact as possible.

You might even want to make a 'myspace mix', with a bit more mid-range, and a toppier bass, going on the presumption that more people will be tending to listen to music off their computer on tinnier speakers that probably aren't big on bass. (That assumption isn't necessarily correct, of course.)