First I must state that I am not someone who would describe themselves as a Stephen King fan. I've read a fair few of his books, some of which I've quite enjoyed and some of which I struggle to remember, but "The Stand" is one of my all time favourite books. I bought the unexpurgated version recently to re-read, after a gap of about ten years, and was as lost in it this time as I was the first time I read it.
Yes, as a couple of reviewers have pointed out, of course you could tell the story in a book half, or even a quarter, of the size but I for one would have felt very cheated. The story is not complicated. It begins with a plague and moves towards a final showdown between, effectively, good and evil and perhaps that could be seen as overly simplistic. The characters, however, are so well drawn that you feel you know who they are and want to know, in detail, how the whole thing plays out. The pace is good, even for such a large book, and the more meditative sequences do not detract from this at all.
Some of the characters are exceptionally good: Nick Andros, the deaf mute, and Tom Cullen for example and Harold Lauder is very finely drawn as a man who finds himself thwarted by life and love and tempted to the darker side. Despite it's somewhat exalted overtones at points, there is a sense of reality to the book which manages to keep it grounded. At times King's writing almost seems poetical, something I never thought I would write in the same sentence as "Stephen King" because I frequently find his real-life character conversations to be rather stilted and pedestrian, unlike his more dreamy sequences.
I imagine for a great many SK fans this could well be their favourite of his. And that an awful lot of others think it's a fair few pages too far and totally up its own backside. I think you should find out for yourself. If you're not sucked in at the end of the first quarter of the book then you never will be but if you are then you're in for a real treat. Read and enjoy.