I agree. Ironically (since he is associated with the 'gardeners' type in the piece), his writing feels too methodical and lineal to me. Also very repetitive. Of his books I haven't liked the first one. The same happens to me with Neil Gaiman, who seems very heavily influenced by King. To me their style of writing is almost interchangeable.
A lot of Stephen King's best writing, he was pretty much out of his mind the whole time on PBR and cocaine. For instance, not really having any recollection of penning Cujo[1].
His later stuff feels much more planned, in that it kind of all ties into his big meta-project of the Dark Tower, even the early stand-alone stuff, that he more or less retcons into that universe.
I actually think that's not a bad way to write! Whatever gets you into the zone or flow. Of course, you have to have the discipline to go back and edit with clear eyes later.
Though Hemingway didn't say that, he was definitely a merciless editor of his own work. I dropped in on this (http://www.themorgan.org/exhibitions/ernest-hemingway) exhibit recently that had early drafts of some of his most famous stories and books and it was remarkable how many whole pages and chapters he chopped out just prior to publication.
I have read about that. And while it would explain the repetitiveness it's independent of how his writing appears to me. Needless to say, a lot of people disagree with my view of his writing.