I agree with you on Jim Lee. The man can draw a fantastic cover or poster, but when it comes to sequential storytelling he comes up lacking for me.I've always thought Jim Lee was overrated. I've never put down a Jim Lee-drawn book and gone "Oh god, that art sucked!" and he is a great artist of the superhero - someone who can draw superhero figures and settings larger than life. Hush is a masterwork of his style. But, Lee is overhyped in the way that Tom Cruise (for example) is overhyped - sometimes Cruise is great (Collateral, Magnolia), sometimes he is one of our best action stars (Mission Impossible movies, Edge Of Tomorrow), and sometimes he gets by on just the fact that he's Tom Cruise (Top Gun, Vanilla Sky), but he's never going to be on the same shelf as say Brando or De Niro or Russel Crowe. Lee is much the same way; he's great at action stuff, but I'd never want to see him draw Sandman, for example, and when he's rushed on a monthly book, I think some of his compositions and figures go from "great" to "average."
Cassaday shocked the hell out of me. He's never done me any wrong until he worked Uncanny Avengers and put in what I would term some very average work at times. I'm used to reading his work and remembering at least one or two memorable compositions or panels per issue minimum; I read the entire first hardcover of Uncanny and remember two or three memorable shots out of the entire book.
But Williams, to me, has yet to turn in a substandard book. There were a few times that I felt Batwoman did not live up to its hype or its initial run of issues (mostly because I think Rucka is a much better writer than Blackman and Williams, even as a team), but even when the story was failing me, the art kept me going and even IMO rose above a story not quite reaching its potential. What should have been done on Sandman (and maybe this wasn't possible) was have half of the issues drawn before the book was solicited, thus minimizing the delays.