Also, Tyler's voice didn't change between that album and their other 70s albums, he just got nervous about it and only sang "Dream On" in his "real voice."
I like Sabbath Bloody Sabbath, but I like all of their early stuff. I agree that it's the weakest of the first six, but most of the songs are still good. Looking For Today is just Okay, Fluff is Fluff, and Who Are You is as awful as anything with the "Black Sabbath" name on it ever was. But the rest is good. It has a reputation for abandoning heaviness, but I think that's the fault of the original CD mix. It was never as heavy as the first 4, but the original vinyl mix is pretty heavy.
Even at the time of their late '90s reunion, Ozzy had trouble singing those songs. He took the title track down to the lower register and cut out he ending, which I think ruins the song. On the live album he did a good job on Spiral Architect, but after that they cut it from the setlist because it was too difficult. I really like that song.