I have mixed feelings about the series - though the most part they are positive.
For the good: The art is quite lovely. Detailed, well transitioned and clean. Also, it is great to have a plot that is more mature, suitable for an older audience. It is intellectual-heavy, and the political/court drama that is simmering just around the corner has very high potential.
Additionally, there are some really attractive guys.
For the so-so: Some of the scenes feel a little long (and this is coming from a History graduate!) There are action scenes, but to me they do feel a bit predictable. Nevertheless, though, they are quite well done.
Some things also are a bit one sided, and preachy: As in "Christians are always bad and ignorant" "Everyone else is smart and advanced". History, even at this time, was a lot more complex then this. I'm not really a fan when one culture is dubbed as 100% awful while another seems to be dubbed as 100% perfect. Yes, there is a mention that the Mangaka consulted a scholar, but I do wish she could have consulted more than one. Alot more than one. A rule of thumb when working in/with history is to consult a variety of eligible sources.
Also, if you are French, you might not like that the main image they get is a bunch of proudful dumb brutish bullies who act before they think LOL
I am on the fence about character development. Angelo does start off as a bit too meek and overapologetic, but he does eventually grow a little better. He becomes a bit more assertive, and takes the role of the teacher at some point. I am glad that he is offered more depth, even if it is just a tad of it so far. Hopefully it will grow further, and definitely hope he will become much more than a possible pawn.
Cesare, well, he is quite perfect in many ways. Only a teen, and he is great at horsebackriding, intellectually skilled, reads people well, very good looking, very humble despite his social status, great at leading military style situations, great at any other hobbies. The only current "fault" that seems to occur is the hint of his future playboyism (Afterall, he did father over eleven kids with different women) but I do sense this isn't going to be portrayed as a negative thing, considering it is a titled seinen series. His other supposed fault that is actually mentioned in the series is his outspokenness, but he always gets out of trouble with this one.
He is also shown to have manipulative tendencies, though it seems to be only on the surface so far.
I don't know why, he is a very good character, but I just feel like something is missing? I want more from him. Something more than just being elegantly dark, dashing and wise, all while smoothly taking control of everything. Granted, it is still technically early in the overall story, so I reckon there will be plenty more in the future.
Overall: It is a really good quality series, and likable enough. Definitely try to keep going over the first couple chapters, as things will progress further. It is not the best manga I have ever read, but it is far from the worst.