I went to Rock in Rio in Las Vegas yesterday and saw the following bands perform:
Coheed and Cambria - not my style
Sepultura - One of my favorite bands and one of the first metal bands I listened to after moving beyond Metallica and Megadeth. Sound was good, but the set list sucked. Jumped into the pit for Refuse/Resist, Propaganda and Arise. Very disappointed that they didn't play anything off of Schizophrenia or Beneath the Remains.
Rise Against - I hadn't heard much of them, but they were alright. I liked them better than the Deftones.
Linkin Park - Never a big fan of these guys, only familiar with their popular songs that got radio play. Entertaining, but not my style.
Metallica - First time seeing them and I was struck by how old they look, made me old to realize I was a teenager watching them on MTV 20 years ago. Lars is rocking a skullet now.
They played a good 2 hour set that appealed to the general audience. My only complaint about their songs choices were the two cover songs they played(Turn the Page and Whiskey in the Jar). Highlights for me were Creeping Death and Disposable Heroes.