I enjoy both albums, but 13 gets my vote. But I agree with the apples & oranges comment.
Ozzy-era Sabbath and Dio-era Sabbath are 2 very different beasts in my opinion. As are all the other incarnations of Sabbath over the years.
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I used to be with it, but then they changed what "it" was. Now what I'm with isn't it, and what's it seems weird and scary to me, and it'll happen to you, too.