So I've pitted the BPL against the Minuteman Library Network. I've been waiting for Pretties for almost a week now from the BPL; I'm at the top of the list, but there are only three copies in the system. There are about ten copies "On Order," but that doesn't mean much. It can take up to a month to go from "On Order" to "Received--In Processing," and then it can take over a week to finish the "processing" part and get the darned book.
Ah, but Minuteman put it in the mail for me on Saturday, the day after I requested it. The only problem with that is that Minuteman has a slow transit system--once something's in Transit in the Boston network, it rarely takes more than two days to get to you. Minuteman can take a week, though this could be due to the branch I use. It's closed on Wednesdays and Saturdays, and I suspect, though I'm not sure, that the Somerville West requests actually go through the Somerville Main branch, adding at least a day to the process.
We'll see which library blinks first.