It depends which ozzy turns up tbh… Saw him a few years ago with sabbath, and it was just plain sad, you could see tony spent half the gig trying to look after him and just keep him more or less pointing in the right direction… Singing was awful, all over the place. When they did the wings thing, he ran off halfway through with only one connected and had no idea, stage hands trying to fix it…
But then, weirdly, a bit later we saw him without sabbath and he was on bloody good form- sure, still obviously an old dude and physically limited, but he worked the crowd, he hit most of the notes, basically looked like a man 20 years younger or about 100% less braindamaged.