When I got my first round of beta feedback, one of the consensuses was that the opening three-chapter prologue-like chunk was dragging on too long and negatively affecting the pacing of the first half of the book.
For the next draft, one of the changes I made was cutting 3,000+ words out of that opening chunk and condensing it from three chapters of four scenes to one two-scene chapter.
The beta feedback I got on that version was that the whole book was pretty much query-ready... except the first scene, which was still not working. Which is awesome, since it's not like the opening of the novel is important or anything. (Self-directed eye roll.)
I tried my best to tighten it up some more, and then posted the first 1,000 words on Absolute Write. The feedback I got has made me realize that I'm pretty much rearranging deck chairs on the Titanic over here. There is just too much WTF in the scene to justify heroic measures to save it.
This is a scary revelation to have one week before you were planning to start sending out queries. But I pulled on my big-girl panties and made a list of everything that I felt had to stay in the scene-- Mary meeting Leopold, most of their conversation, some worldbuilding aspects, tension between the magic-users and religious extremists-- and mentally let go of everything else.
Interestingly, I got a new idea almost immediately, and as of today have worked out a full outline, including dialogue. The outline is 1,500 words, but my outlines tend to be wordy, so I'm hopeful I can craft a 2,000 word scene that makes sense. My plan is to work on it two hours a day until it's done, and then post the first 1K words for feedback again, and rinse and repeat until I have something I'm happy with-- and which at least gets me a "this doesn't suck" majority opinion on the AW forums.