Slash keeps his guitar too low, so he can't really use his wrist properly because of angle between his arm and strings. Sambora is doing everything properly, in a way that John Petrucci and few others does. And you can see it - especially nowadays when he can play sixteenth in 126bmp (born to be my baby, keep the faith MSG version and few others), not by shaking his arm but working a wrist. If you are a picker you should notice that. Slash is never gonna do that. Neither is Perry.
Sambora have on of the most loose and properly working technique. And in concerts like Tokyo 2008 you can see his control over harmonics, muting and everything else. To me he is very technical player. Perfect learning material.
Musically of course he can be very interesting or completely boring. His solos are generally more and more repetitive, that's true. I think his playing was great in 2008, and really poor sometimes in 2010-2011.
And the worst of his playing I've heard is on this new album. Not even one good solo to me. On the other hand he is doing great in ambient, ballad U2/Jeff Beck guitar painting (I mean Forgiveness Street, You Can Get So High).
And what about Tokyo 2008 - please take a look here
His palm muting, harmonics, whammy work and everything else is beyond perfect here (not even the solo, just whole song). I can't imagine anybody doing this so perfect, subtle and musical. And still rocking.