Jordan had the whole series plan down before he started writing; the middle grew in the telling, but as I understand it there was never any doubt about there the end would be. So "holding pattern while he figured out where he was going" is not the failure mode there.
If he had the plan down, then why the 3 or 4 books of nothing happening and pointless meandering?
Sorry, but it IS a failure....he trailed off into minutae in the middle of his story...that is a story telling 'DON'T'.
If he couldn't figure out where he was going, then in my opinion, he needed to sit down and work that out, not just write more books with the idea that eventually he'd work it out.
Knowing the end is important, but just as important, or possibly more, is HOW you get there.
We know Dresden is going to survive, in The Dresden Files books, we KNOW that ending. It's what he does to solve the problem and how he does it that suckers us in!