My memory of that book is pretty vague -- which is saying something itself -- but from what I do remember, my opinion is pretty much dead-on with yours.

It's not bad. It's kind of fun. You just finish it and go "...Okay. Was that all?"

Still not as bad as a couple of her early works, though. *wry* And I say this as someone who absolutely adores several of her books. But she is definitely a writer who has her on days and off days, as you say.