James' screams always sounded kind of raspy to me, even back in his heyday. Now, they are a bit raspier and slightly diminished now, but there's still plenty of power there, power that a lot of (rightfully) well-regarded singers would still kill for. But part of the appeal with the screams, at least to me, is that they aren't just these big clear notes--they're really high, but they have balls. And they just explode over the top of the song as a result, in a fashion I haven't heard many singers successfully emulate (whereas a ton of singers, and just about anyone really, can do the big clean notes with some practice).