just stop after book 4. the rest of the books do not exist.
but really, after his accident stephen king's writing really changed. I wouldnt say worse, but the dark tower took a hit as he was halfway through the series when it happened.
Except for maybe Martin and Tolkien, who I consider on a whole different playing field..."The Dark Tower" series really is right up there with some of the great fantasy series.....for the first 4 books....
I'm about half-way through book 5 now, and I'm not seeing the massive dropoff in quality that has been alluded to.
The change in narrators has been disappointing (though also not as bad as Audible reveiws would have me believe), but I'm still really enjoying it.