I liked it...but I didn't LIKE it, like it. The characters were a bit to one dimensional to be really engaging, and the plot a bit predictable. That said, the way the author weaves the alchemy into both the surface story -- Emilie's activities, and into the psychological story -- Emilie's development, were really enjoyable. From reading other reviews, it seems that many of the people who didn't like the book were not picking up on the multiple layers of alchemical process. I think, perhaps, it was a bit too subtly done, and I say that as a neutral comment, not a compliment or a criticism.
There are some books that I would recommend to anyone standing still long enough for me to say, "You've got to read this!" This is not one of those books. I would definitely recommend it, but only to a certain sort of reader.