I'll chime in on sknight's behalf:
Guitar One December 2006-
G1-"DO you have that same chemistry with John Myung (as you do Jordan Rudess)?
JP- "The thing that I love about John, and it's always been this way, is that he knows exactly the right thing to play. Dream Theater is about a certain musical concept, and John is the core of that concept. He might be sitting there quietly listening to us go back and forth with notes, and then he'll drop the bomb with the best riff of the record."
Clearly, based on these words directly from John Petrucci, Sknight is correct.
Oh wait..........nevermind I think this clearly stated, consise statement straight from Petrucci's mouth actually completely shoots down what Sknight said. My bad.