My ear says Satriani is ALL gimmicky. That's his stock in trade. Not that it's bad...
When I said Joe is never gimmicky, what I meant is that his playing is always with purpose, not "watch this amazing useless technical trick I can do with my guitar - gee aren't you amazed that I can do that?" It was flashy/no-soul pretenders (like Steve Vai) who did that and that is what sunk the guitar-wizard scene that I spoke of. A bunch of guys who heard Joe said to themselves "I'm gonna learn to play like that" and were able to match (and even exceed) his speed and skill, but they never matched his awesome musical vision.