The style of the original Gunslinger was/is very different from King's "normal" writing. This throws a lot of people off. Personally, I really enjoyed The Gunslinger when I first read it as a series of stories in F&SF; then I was able to get a copy of the first hardcover edition from Grant and enjoyed them all over again. I'm not a big fan of the revised Gunslinger, however. It lacks the weirdness of the original.
John
If it ain't broke, don't fix it.