I think what most miss about Zack's talent, is his dynamics on guitar, he has produced some of the best and strongest 'walls of guitars' in recording, there's really not anyone like him and he doesnt resemble anyone else's style, (in my opinion), I guess you either hear it or you dont, I agree he is at his best with Ozzy, and dont see Ozzy with a different guitar player other than Zack Wylde, unless its Jake E. Lee, who I thought did very well with the band Badlands
YouTube - Ozzy Osbourne || Miracle Man || No Rest For The Wicked Tour 1989