DIO isn't bad, well he is no ozzy, but heck heaven and hell and mob rules, are the best non ozzy albums from sabbath.
heaven and hell better then tech. ecstasy and never say die? mayb, well prob not... well mayb
holy diver is also better then some ozzy albums
I would like to see anyone try and fight ultimate sin vs. holy diver
no way Ozzy is better then Dio in that battle
Dio is was also a much better song writer then Ozzy.
Geezer was so glad when Dio joined up because he could stop writing the songs and get on with playing.
as for Dio vs. Metallica. well I never really liked Metallica. don't see the point to hearing sabbath, zeppelin, and deep purple being played really fast with a poor voice over it. why not just listen to Master of Reality @ 45 and you will hear what metallica is all about
(don't want this to turn into a flame topic between Metallica vs. classic 70s rock cause I can just look at album sales and show you what one more people like

)