This is a book that's doing a few of the things I like best and one of the things I like least. On the whole the "like best" trump the "like least" by far. The things I like best are when people are trying to figure out new things. This, like thistles and haycorns, is what Mrissas like best. Whether it's a magical system or a scientific one or whatever, I like it when people are trying to find out how the world works. I am given to understand, mostly from reading diatryma's book posts, that the sequels to romances are often the sisters, cousins, and aunts of the previous couples also Finding True Love, and in that case this is very firmly a fantasy series because it is doing fantasy things, not sister, cousin, and aunt things. So go that, as far as my tastes are concerned.
Also in things I like: I am dubious about marital discord, but in this case I liked the fact that it arose from cultural disconnects about what spouses are "expected" or "supposed" to share with each other, and I found that entirely realistic in the culture in which this was set and also entirely realistic for the particular characters concerned.
The thing I like least: I don't like skimping on the denouement. At all. And in this case, the event that occurred and the denouement that was skimped on...was pretty emotionally major. So there's running around dealing with the sort of Napoleonic/post-Napoleonic/what on earth is Old Boney doing in his exile?-era France and Belgium, and then there is the dealing itself, and then major emotional incident, and then wham, done. And...I'm trying not to spoiler here, because the book is just now coming out. But I really feel we could have done with a bit more in the way of falling action, is what I'm saying here, in order for the emotional shape of the book not to feel like running me into a brick wall and leaving me there with a concussion.
It was, however, a very sturdy and well-constructed brick wall. I don't want you to think it wasn't. Lots to like here. Lots of fun things. And it's not an Adam Stemple Singer of Souls ending. It's just the ending, uff da. The very audience for this book is the audience who will be most brick-walled, I think.