I'll begin by saying I'm not the biggest MCR fan. I like some of their songs, but save for a couple, I'm not extremely familiar with their catalogue. I went to the concert because of someone else, and I figured 'why not?' since I don't mind them.
With that said... They sure put on an amazing show. I was initially worried, that just because I don't know a lot of their music, I might not enjoy the show so much. That wasn't the case at all. From the moment they first took the stage and went right into Na Na Na, I knew that they were all business. These guys were for real. They kept up the quality of their performance, and even songs that I wasn't familiar with, I still found myself really enjoying. Now after the show, I've looked up their setlist and have added it to my iPod, so I can start listening to them more, as I clearly have been missing out.
I wasn't overly fond of Neon Trees, and Architects were alright, but MCR made up for them easily. My only real complaint would be the size of the venue. It was a little small, and frankly I am no fan of the Edmonton Event Centre. Next time they come through, I hope that they can move up to play the Shaw, or maybe even Rexall, because if anything would keep me from going again, it would be the location of the show.
Bottom line: I'd recommend seeing them if you enjoy their music (even just a couple songs, like me), and I would definitely consider seeing them again.