Opening act: I'd love to be able to tell you who the opener was, but everytime their singer said the name of the band, he mumbled it. Unfortunate, actually, because I enjoyed them and would've considered buying their cd at some point (I was too lazy to trek back to the merch booth).
Counting Crows: Exactly what I expected from them. Beautiful beautiful beautiful. Had they not fit Anna Begins, Rain King, and Round Here into their set, I'd have decided to boycott them entirely. I was not disappointed. :) The stage show looked good (on those occasions that I could see the stage), but wasn't anything to write home about. All in all, seeing them in concert was well worth the money and I'd love to catch them again.
John Mayer: Let me preface this by remarking that I'm not a huge Mayer fan anyway. I came to the show solely to hear Adam Duritz. That said, I can appreciate a good performance even if I'm not a huge fan of the music. He ALMOST managed to get me to enjoy his set, at first. His guitar playing was excellent, the songs he played weren't too bad. However, everytime he went into a guitar solo, he'd make a very blatant indication that he was going to do a solo. While he is a fairly decent guitarist, I've heard enough people imitate Van Halen over the years. The solos just weren't original at all. Then there was the talking guitar. OMFG! There is nothing more sad than an accomplished artist having a conversation with his guitar. Do you see a lot of Peter Frampton fans still? No. Why? Talking guitar tricks are lame. We left about halfway through his set, right before he started thanking everyone for sticking around to hear him play. I'd imagine he was kind of miffed to come out after the Counting Crows set to discover about half of the audience had left before he even made it to the stage.