I just finished re-reading the entire Promethea opus (thanks Hoopla!), and it is simply amazing. I love Watchmen as much as anybody, but this is a greater work, with more depth, better art, and truly touching. I can’t speak to the metaphysics, but this is clearly closer to Alan Moore’s heart. I read his (incredibly long) novel, Jerusalem, and he deals with similar issues of time, the soul, human destiny, angels, demons, Christianity’s place in humanity’s collected mythology, and, above all, the crucial role of storytelling at the core of being human.
I would say there’s no comparison in the art, but there is: J.H. Williams III is by far the greater artist than Dave Gibbons. Gibbons is a wonderful comics artist. J.H. Williams III is a wonderful artist who works in comics. To me, there’s a difference. His virtuosity in different media and styles, the varied characterizations… To be fair, Gibbons, too, is capable of presenting people of different shapes and ages and kinds. But Williams III is just more like a window onto humanity.
One last fanboy note. Especially now, looking at the imbroglio of the 5 Swell Guys, doesn’t the conflict between Stan and Marv seem like a classic case of white rage? It’s not stated that way explicitly, but Stan sees Marv as being in competition with him, and this is utterly unacceptable for him. You could also, of course, take Stan at his word, that it is simply that his and Marv’s roles have some overlap (genius vs. builder), and that is the cause of his hatred and jealousy. But I don’t think Marv’s being “the black guy” has nothing to do with it.