I think that on the whole I prefer Satriani as a songwriter and Vai as a performer/player. Like DreamRyche said, I can pick up just about any Satriani album and listen to it the whole way through and be entertained without losing interest, with Vai the only 2 I can do that with are "Fire Garden" and "Passion and Warfare". Vai is sometimes a bit too crazy for me :) Some of his songs like "Tender Surrender", "Bad Horsie" and "For The Love of God" (to name a few) surpass Satriani's work in my opinion. A friend of mine actually hates Satriani and thinks he's a crap player technically which I can't agree with, he says Satriani uses legato all the time and it's all he can do. I agree, he does use legato loads, but thats just his style.

I think on the whole they're both equally as good in their own right, and as you can tell by the fact they always give each other praise and do G3 together, they respect each other as players and musicians.

- J