I have. The self-reflexivity was interesting, but the quality of the story was lacking in the later books, as you've already discovered most likely. I was dissatisfied with the ending, and while the metaness was interesting, especially to watch as King manipulates the entire relationship between book, author and reader, the book started out as just a really involving story, and would have benefited without the agenda change that appeared after Wizard and Glass.

I've read all seven books. I read the first when it initially came out in paperback in nineteen-whatever, and when all seven volumes finally came out in hardcover, I bought the hardcover reissues (including the revised version of The Gunslinger, and the re-release of The Drawing of the Three with Phil Hale's revised artwork) and read them all straight through in a six-week marathon.

I think the revised version of book 1 is one of King's best novels, and I think one of the brightest spots in the series is Father Callahan's side-story in book 5. I don't think that, without King's name on the front or its place in a bestselling series, the seventh book would even be considered publishable--it reads like Dark Tower fanfic, and it breaks continuity both with earlier books in the series (even taking into account the revisions to book 1) and with other books in the King catalog (identifying those books would constitute spoilers). Much of the plotline of books 6 and 7 appears in a more well-written and concise form in another King book (which again, I won't identify). I found the postmodern hijinks to be pretty tired, and the final pages of book 7 are an insult. (Nice artwork throughout, though.)

Though book six's plotting is somewhat scattershot, the book is academically interesting, if only because King has consistently had trouble throughout his career in depicting credible African American characters (see the Magical Negro characters in The Green Mile, The Shining, The Stand, etc.) Not to give anything away, but I find the Susannah of book 6 to be drawn much differently than the Susannah of book 2, written seventeen years before.

the final pages of book 7 are an insult

I don't have time to say too much at the moment, but I disagree with that, though it's obviously something that will vary from person to person. I found the ending perfectly satisfactory (and something I'd expected as one of the most likely ways things might turn out - though I wasn't certain.) I also enjoyed the self-referential nature of the later books and thought it was handled quite deftly.

The absolutely ludicrous resolution of the conflict with the Red King is what pissed me off in the last book.

Otherwise, in general, I think all of the first four are excellent - I'll return to them and reread them any time; the final three are about comparable to each other but a decided step down in quality. I had a certain feeling of reading out of obligation, and don't expect I'll return to them any time soon.

Quite a side note, I read Wolves under the worst circumstances of my life, so that one in particular - although I thought the story wasn't bad - has extra connotations that will keep me from returning to it for a long time.

Of the five I've read, Drawing Of The Three was my favorite. Read it last November while on vacation in the UK, which might've had some positive influence. The Wastelands was pretty great as well. Wizard And Glass, I hate to say, just didn't sit well with me. The previous three had wrapped my interest around the "current" ka-tet, so hearing this grand tale about the original ka-tet just wasn't as fascinating.

Book Five. I'm okay with most of it, particularly Callahan's tale, the Sisters of Oriza and Andy's fate ... though I am starting to wonder just how King is going to manipulate this metafiction into anything satisfying.

And did I miss entirely the nineteen words that Gran-pere said to Eddie, that Eddie said to Roland? I know what secret was revealed in general, but why tell me there were so many words if the actual words aren't shared?

sand, I felt exactly the same way about W&G on my first reading. I recently bought books 5-7, and started over from the beginning, and my second time through W&G, I really liked it. A lot. I adored Blaine, so Wastelands will always be my favorite.

I loved books 5-7 (especially 5) and I loved the ending (other than, as wolfdog said, the Crimson King resolution), and if that makes me a dissenter, so be it. I just read to be entertained, and I was.

Here's an applicable song.

I'm insane but not yet crazy
I will never let you go

My biggest beef with it was the aforementioned breaking of continuity in book seven. That really bothered me. He had been building that up for years in various works, and then they come out to not really matter all that much at all. There was some line in book seven somewhere about how those other tales only represented possible futures/weren't authoritative/etc. Yeah, whatever, nice excuse for your lazy writing, failing to count those in, after leading the readers to believe that they were authoritative. Part of the appeal of the series to me was that it wasn't just these seven books, it was this vast tapestry.

I loved Wizard and Glass, and found the side-tale absolutely enthralling, but like Wolfdog and Wolves, it's now associated with something I'd rather forget and I doubt I'll read it again anytime soon.

There were also a few anticlimactic incidents (the Crimson King resolution among them) in book seven that also let me down.

That said, I did like the circular nature of the ending. It was... imperfect, but okay.

I guess I should add re: the tapestry aspect, one of the coolest things about it was that if you wanted you could go searching for clues, signs and portents, in his other works. The main series stood on their own, but there was this whole extra aspect. To suddenly have those dismissed as non-authoritative annoyed the hell out of me.

Ack! Kosh, that was a spoiler!

Gah, I'm so sorry! I was trying so hard to keep it acceptably vague, too. :(

Prospero: [...]the final pages of book 7 are an insult[...]

Wolfdog: I don't have time to say too much at the moment, but I disagree with that, though it's obviously something that will vary from person to person. I found the ending perfectly satisfactory (and something I'd expected as one of the most likely ways things might turn out - though I wasn't certain.)

To clarify: it's not so much what happens at the end of the novel that I find offensive (in my eyes that was more a copout than anything else, but as you say, that's a matter of opinion). It's the fact that King actually breaks into the narrative to pre-emptively scold his "Constant Readers" who might have the nerve to dislike the ending, and then follows that up with an afterword in which he admonishes these same readers not to try to find his house.