I don't want to knock Stephen King because he is actually a really good writer that does not necessarily write what one would consider airport trash. Okay, my English teacher would disagree with me heartedly, but that is one of the beautiful things about literature: you can disagree on the definition of literature. I guess his idea was that most students would read King simply because of the horror and the supernatural aspects, and that out of all of the King essays that he had read he had never seen anything that was deeply engaging. Also, considering that when you walk into an airport bookshop (and I have done so a few times now) all you seem to see on the shelves are what would simply be popular novels (Tom Clancy, Jackie Collins, and of course, Stephen King). However, the next time I walk into Melbourne Airport I will make an effort (if I remember) to go into the bookshop there and see if Life of Pi is also on the shelves (I bet it is).
Stephen King does not write standard fantasy. What I mean by standard fantasy is where the author is influenced by Lord of the Rings and tries to write something just as good, or even tries to better it. Basically the story goes that some guy from the backwoods who would normally amount to nothing turns out to be the guy mentioned in some long lost prophecy (which Frodo never was), goes out and saves the world, and then becomes king (which never happened to Frodo either, he ended up going off to the world of the Elves because he had become tainted by the ring and could no longer live in Middle Earth).
King is different because his characters are dark and flawed, as is the case in this book. It is also an amalgamation of fantasy and western (which is an amalgamation that works well because the world of the western is wild and untamed that the nameless cowboy attempts to civilise). I cannot remember too much of this book, and I know that I never really made it past this book simply because, in a way, it seemed to me to be quite dry. I do believe that he has completed the series, but I never really had an idea, from this first book, where the series was headed. However that does not necessarily mean that King's writing, or characters, were bad. On the contrary, they differed from your typical peasant come prophetic hero, come king, type of flawless person who was the epitome of good (which is what Frodo was in a sense, but I would rather suggest innocent rather than good, and even then Frodo was not immune from the ring's corruptive influence).
In the end it really comes down to what you like. If you do prefer the heroic fantasy with the flawless hero (meaning that you did not like Michael Moorcock) then maybe this book is not for you, but if you are looking for something different, something that does not even attempt to mimic Lord of the Rings, give this one a go. I can't say whether you will like it or not, or whether you will get past the first couple of pages, but one thing that I can say is that it is different.