I saw him at Warped Tour over the summer... I don't know, it was alright but he toured with a full band which just defeats the purpose of his music. I didn't really like his set that much--he did a Beatles cover (I love The Beatles, but I wasn't at a Beatles concert) and he sang the National Anthem... which, I mean, really?! Nothing against the Star Spangled Banner, but...At Warped you have like a 30-minute set and he totally wasted a lot of it with pointless covers.
I also think his head is getting too big lately.
Maybe my opinion of his live shows would change if I saw him at a more intimate concert. IDK. He did really incredible live shows back before he gained so much popularity: http://www.youtube.com/watch?v=hAgU6Uu2k7o&feature=related
Like in this video. <3
He started out so great and humble and now he just tends to irritate me. :/