RJ changed his mind a lot on how many books it was going to be. He tried to sell it originally as a trilogy! It ended up as 14, and looking at the finished books it is clear it was never going to be done in any less than that. And, maximum respect to RJ, but I suspect it would have been 15 or 16 had he lived; Sanderson is a much pacier author. The last 3 lack some of the subtlety of Jordan at his best, but they do round off the series well and answer most of the outstanding questions. I'd certainly recommend them.