I've long been a fan of Sarah Beth Durst. Her stories cover a wide variety of genres, and are always worth reading. This book was quite unlike anything else I'd ever encountered, and while it isn't my favorite of Durst's, it's still interesting.
My favorite character in "Vessel" was the desert. It is beautifully described, and despite the difficulty of living in such a harsh place, I came to understand the fierce love that Liyana and the other desert people had for their home. I also loved the mythical creatures that inhabited the desert, particularly the sand wolves and sky serpents.
The human and deity characters were more or less interesting as well, though they will not be counnted among my all-time favorites. Liyana is mostly practical and competent, with moments of passion and emotion. I am a practical person, and female characters whose main characteristic is "practicality" are few and far between in fiction, so I enjoyed seeing the world of "Vessel" through her eyes.
My main problem with this story--the thing that kept me from giving it 5 stars--is the pacing and plot development. I felt that the pacing was uneven; so much of the story was spent just traveling from tribe to tribe, without a clear endgame. I kept waiting for the "real plot" to start, and then realized I was more than halfway through the book. The ending seemed abrupt and too easily resolved, and not all my questions were answered. (So what happens with the drought now? You know, the big problem that was killing the desert people AND the people of the empire?)
The Empire was underdeveloped, as well. I came away from the book with only a vague, amorphous idea of what it was even supposed to be. (A big empire that's suffering from drought, basically. Very little idea about its people or culture or customs. I would have loved to see that better developed, and by extension, the character of the Emperor. He is a very major character by the end, but still I felt that I barely knew him at all.)
Bottom line for me: This book is worth reading. It has some interesting characters, among which the desert itself is the most fascinating. The quandary about the vessels and the deities that "kill" them to inhabit their bodies provokes thought about the nature of sacrifice. Pacing is uneven and the plot seemed a bit muddled and meandering, but I would still recommend giving this one a chance. 3.5 stars.