I will say Logan did an awesome job as Simon, his scenes were great. But I loved Gerard and Michael as well. I loved the scene where Michael did that little dance, I don't know why but it's my fav part. I will say though that I want to watch Percy Jackson because of Logan. He's a very good actor.
No he wasn't the only reason I watched the movie. That movie looked very badass when I saw it previews. Gerad Butler, the dude who played Castle, Logan was alright in the movie he was a bad boy!!! xD but, other than that. All through out the movie was the most epic movie I ever seen since 300!! =O