Well, I have gone through other great series and I have to admit I forgot to mention the really great
"Otherland" books by Tad Williams, a great series, I really chewed my nails for every new book to be translated and published, but even there the end was not that fullfilling, but maybe more, because I was sad that there will be no more great books to follow.
But the "Dark Tower" end was unfullfilling in an other way, I can not explain it, but it was like buying a car with three wheels, a great chassis, nice engine, beautiful colour, but a lacking wheel... I do not know...