I literally just finished it about 3 minutes ago, and I will say that it was a very good, mostly enjoyable Voyager novel, which is something I haven't really had an experience with.
It took me a while to get through it, partly because of my ADD reading style, and partly because it felt a little plodding and repetitious at times. (Emphasis is on felt, as I'm not a big Voyager fan to begin with, and considering the fact that previous entries ranged from "meh" to "ick", and considering that this had the big task of breaking with all that, I'm willing to take what I got, and what I got was good.)
I liked the scope and range of the book, considering that it covered 2 years and had to take into account the End Of Life As The Alpha Quadrant Knows It, AKA the Borg Invasion of 2381 AKA the "Holy-Sweet-Mother-Of-Mercy-I-Didn't-Expect-That-Hot-Damn" series called Destiny, and what was most enjoyable was how it sort of accepted the Golden-entries, but then built upon them and made everything better.
The whole Klingon and B'Elanna/Miral part of the plot kinda didn't work so well for me, which is interesting because I liked B'Elanna. I'm not a big fan of Klingons anyway, and the whole "OMG Miral is important" aspect felt a little forced, as if to say "Well, gee, we don't have enough chaotic things going on already for the Voyager crew, so let's introduce this and cause more conflict". Again, it's a personal thing. There were times when I felt like Full Circle was a two part miniseries, which helped me get through the parts that I didn't enjoy so much.
I liked Afsarah Eden, hated Admiral Batiste, and am not really sure how to feel about Admiral Montgomery.
I liked the way Seven/Annika was portrayed because it felt so realistic and in line with what I would have thought she would have felt after the Caeliar removed her implants.
All in all, it made me care about Voyager beyond the little bit I had after watching some episodes. And I'm looking forward to Unworthy now.
Good job.