I went Sunday last year and it was awesome. The closest thing to a downside is that I'd have rather seen Metallicas Friday set instead of the one I saw. But the other bands I saw on Sunday were better than the other bands that played on Friday. No regrets, money well spent.
Well I did burn the top of my mouth on a slice of pizza which was delicious, so that sorta sucked I guess. But I got to see Metallica, Judas Priest, Seether, Breaking Benjamin, Pennywise, Skillet, and a few others and it was awesome. Weather was incredible too.