lalimacefolle, Petrucci is an amazing guitarist. His chops are unreal. Playing Petrucci's stuff is so difficult. Do me a favor and try to play some of his stuff. I have listened to him for a long time and I have seen him a couple of times live. Some of the melodies he writes are incredibly difficult to play. Try playing like "Under A Glass Moon" or even the melody in "take the time" (both on images and words). I guarantee that you will be shocked at how hard it is to play. That is just technique alone. His material is so innovative. I don't know how you can listen to him and not think he is amazing. Honestly...I can't believe that you are a guitar teacher...and have been playing for any length of time without hearing him play a long time ago.