That's the impression I've been getting from what I've read on the internet. A lot of people consider this and The Dark Knight Returns to be the best comics ever, but then on the other hand a lot of people considering The Dark Knight Returns to be the best comic ever and Watchmen to be nowhere near comparison. It's kind of interesting how one-sided it is in that regard. Your description of it sounds like what I've heard from a lot of comic vets who don't happen to be so far on the side of loving both, and I suspect that's probably where I'll fall into things as well. But I'll reserve judgment until I read it... and I'm quite sure that I'll enjoy it regardless.
I really do have to bestow more praise upon TDKR, though. It's very cool to read after seeing the Dark Knight film. Obviously the things aren't related, but you can definitely see how much inspiration was drawn from the thing in terms of tone. And if you want a literary work, you've got one there. Sure, it's still just a comic, and maybe some of the stuff is just slightly inflated for the sake of an idea or two, but it's really quite a beautiful thing that (thus far, at least) hasn't felt at all cheap or exaggerated. I'm really impressed, and I think it's definitely the kind of thing that bears several repeat readings due to its depth.