Having the comments of various readers to guide my editing was extremely useful, but didn't solve everything. For example, there was one short lyric which more than one reader had queried, and I can see why. I feel it earns its place, partly because it helps to balance out the longish poems which are prevalent in the book, but also on its own account. In particular it draws on and informs some of the other pieces it sits among.
Of course this is mere self-justification, and the readers may well be right. It's so difficult to get a proper perspective on one's own work, and yet the flawed perspective you do have is, whatever a theorist might say, privileged. The comments of readers are useful precisely because they come from good poets, but if you followed every other poet's advice – this is analogous to the idea of the 'workshop poem' – you'd risk knocking off the edges that make your work distinctive.
So – I left it in, and while I have no idea if I made the right decision, it's now out of my hands, so I can't worry about it any more. Much.