I got seriously bogged down in "Wizard and Glass" because my tolerance for impending tragedy isn't all that great--certainly not hundreds of pages worth. If I know everybody's going to be stupid and die, you have to have SOME motive for keeping me turning the pages, the setting wasn't doing it, and tales of young love didn't even interest me when I was young and wanted to be in love myself. Finally I just gave up, skipped to the end of the most-of-the-book-length flashback, and went from there. Once out, my interest was rekindled.
I have a love-hate relationship with these books. The thing is, I don't much like large chunks of them. I don't read westerns, excessive crudity makes me uncomfortable, and I don't like guns. Futility irritates me. And I hate time travel, even in small doses. All this adds up to not even the sort of distaste that leads to fascination, it's just plain "Ew, no, I'll be over here," kind of thing.
And parts of 'em are bloody brilliant and fascinating and make you go "Damn," and wonder where it hooks into everything else.
The overall effect is sort of like one of those dreams that almost a nightmare, but which is just fascinating enough that you don't quite want to wake up and have done with it. It's interesting. It's got so many weird loose ends and dovetails coming together with other bits of King's work that one can conclude A) King is an incurable romantic and wants to make sure everybody in his books gets what's coming to them, if they haven't yet, and gets redeemed if they deserved it and weren't. B)...well, B's complicated. It reminds me of what I was thinking about Neil Gaiman writing "Sandman" and saying that he kept putting in minor characters and outs and random bits just so that he had something to use later, something to give him an out, whatever. The importance of leaving trails of breadcrumbs, as it were--you might not need them, you might not use 'em, but there they're if you need it. Dennis McKiernan, shameless Tolkien imitator, (who's work I really can't stand since passing puberty, but anyway) said something like that in a prologue, although he called 'em "red slippers," after a Sherlock Holmes case that didn't exist--things that litter the landscape that you generally don't follow, but which you can occasional pick up and actually get to be bottom of. King leaves a lot of those, and often uses them well (and presumably I've forgotten the ones that didn't)--for example, there's a line in "It" with a so-minor-he-doesn't-even-get-named character that winds up as the focal point of "Dreamcatcher" and I rather doubt that he knew the one's story when he wrote the other years earlier, but there was a trail of crummy slippers to follow back, and then we can all be wowed at how well it fits together.
The Dark Tower books are like towers built out of left breadcrumbs. Which is a fabulous effect, but which almost requires that you have a career as a terribly prolific and best selling novelist spanning several decades to really pull off. You end up with this enormous self-referential kind of mythos. You couldn't build it from the ground up if you tried. It adds an Easter-Egg hunt element to the whole thing--spot-the-reference, spot-the-in-joke.
So I guess this just sort of hammers home for me the importance of leaving bits in that might not go anywhere, so that you've got 'em later. If they don't get used, then, eh, chalk it up to local color. If they do get used, people can be in awe of your astounding plot powers that sowed that seed five hundred pages before it got used, and whether you reveal the sorry truth is dependant on your own moral fiber. This flies in the face of some common wisdom, on the importance of lean, mean, brutal editing, mind you, and reminds me of some comics I've read, which were admittedly fast-paced and as streamlined as a greased barracuda, but they'd sliced out their breadcrumbs and were as self-contained as a bullet. If something came up, you bloody well knew it'd be used later. And I dunno, maybe that's better. Editing's not my strong suit. But it was oddly flatter for it--there wasn't the illusion of a landscape behind it, crisscrossed by trails of breadcrumbs.
And now that I appear to just be rambling, I'll go ramble elsewhere...