I like the Emperor's Blades, but, given the many new epic fantasy series of the past few years, this isn't at the top of the list. It is clearly in the grimdark (Ambercrombie, not Rothfuss) camp - horrible events, moral ambiguity, lots of death and fighting. While not bad, it doesn't seem to add much interesting to the genre, and has some questionable choices.
Some of the questionable choices are worldbuilding. While there are lots of nice touches (sky ninjas on giant birds!) a lot of the rest falls somewhere between cliche and nonsensical. On the cliche side, this book mostly consists of the training of two different heirs to the throne. One is being trained in a monastery with (surprise!) taciturn, koan-spouting monks and has to find the meaning of their zen-like lessons. The other is being given hardcore military training with (surprise!) taciturn, tough-as-nails officers and has to overcome bullies and physical challenges. On the nonsensical side, apparently neither of the heirs to the throne are trained in anything having to do with ruling the empire that they are inheriting. Instead, they are subject to conditions that, for no really good reason, seem designed to have a very good chance of killing them.
The other questionable choices have to do with tone. There is a third member of the royal family, a daughter. She, like many of the women in the novel, gets a lot less time on the page. And most of the women we encounter get abused, tortured, or worse. It adds to a sense of discomfort throughout the novel.
Nothing here is awful, and the reading is great, but the book seemed rather forced, with motivations seeming muddled and the world not really cohering into a whole. The action was often well-done, but I think there are better new fantasy series to read.