He's really hit or miss for me. His run on Ultimate Spider-Man was fantastic and I liked some of the things he did with Superman, but there's a lot of junk mixed in there.
Miller had his time in the spot light, but he's never really been able to recapture the magic of the Dark Knight Returns, 300 or Batman Year One. His Superman Year One was especially bad.
Gonna be honest, I never read that one. I already have to read enough of this stuff for work, so it's tough for me to justify going back to read material from an author that has consistently let me down.
The Stan Lee of the X-men