My view of audition rotations is that if you're weak on paper, it can certainly help, and if you're strong on paper, it can certainly hurt. When your grades and scores haven't been that great, an audition rotation is an opportunity to show a program that you're better than your scores indicate. When you look like a superstar on paper, I feel like the only thing you could accomplish by doing an audition is showing them that you do have some flaws (unless you're applying to a super-competitive specialty, in which case you should probably do several auditions even if you're a superstar).
You of course need to take into consideration how good your clinical evaluations have been, as well as your comfort level with needing to be "on" for the entire month.
I'd recommend doing an away elective (not necessarily at your #1 choice, and not a sub-i) for anybody just to see what things are like somewhere other than your home institution. I think it gives you some idea of what to look for on your interviews elsewhere, and helps you figure out what you're looking for in a program.