I had trouble summing enough will to finish DAF. I found it slow and totally uninteresting. Easily, IMO, Fleming's weakest Bond novel.It's one of Fleming's most underrated in my opinion. I think it moves very, very fast.
I think TMWTGG is the weakest, but for obvious reasons (ie Fleming died before he could revise it). Apart from that, I agree with you: DAF is the next weakest.
But, let's be honest, even weak Fleming is better than the best of Gardner...