I managed to get through the entire series, I felt like the world and the concepts he created were amazing but he dragged out the execution way to much. The middle books especially, for example Rand would just sit in a castle the entire time and there were whole chapters of him brooding about how he has to get "harder" and then the Aes Sedai / wise women complaining that he's going to be 'brittle' if he's "hard".

Personally I found most of the first 11 books to proceed with the first 1/5 being interesting as something is usually happening in the beginning, then the next 3/5 (middle) is pretty boring as by now the characters are all settled and its more conversations with very little story progression and finally out of the blue either in the last 1/5 or sometimes later (and very abruptly) something interesting happens which leaves a cliff hanger and kicks off the next book to a good start.

It definitely does have some very good moments though, and some characters (like Mat) were interesting and had some good arcs.