I really enjoyed this, and am eagerly anticipating further updates.
Although at five volumes the story is long, it has plot and a good set of characters, which helps. However, if you are looking for a light, I'll-just-skim-through-it read, this isn't it. The dialogue is essential to the complex, aristocracy-based plot and half of the manga is focused on inheritance rather than any tangible romance.
That being said, I loved the relationship between the two main characters. I particularly enjoyed the first few and middle volumes, watching the power balance shift and Akihito's growth into the lord he becomes. I liked watching Akihito struggle for power over Katsuragi and laughed at every time he was coolly cut down, just as you thought he was finally about to get one over. I liked the rape, I thought it worked with the character's emotions, and unlike some other reviewers I thought it actually enhanced the dynamics of their relationship, and worked with their romance as K. slowly fell for Akihito.
I also loved Katsuragi as a character; his cool, mature aloofness, and sometimes very harsh behaviour, combined with his unexpected, but absolutely adorable softening as the series progressed (especially during some of the sex) worked together well with Akihito's youth and unexpectedly fiery temper and immaturity (although he mellowed out as the series progressed). Katsuragi definitely made the manga for me (at the start, he reminded me a little of Sebastien from Kuroshitsuji). And Katsuragi is a MAN, which I loved. No girly ukes here, this dude could seriously kick some ass if he wanted.
Despite this being set in the taisho (?) period (not one of my favs) and being a master-servant relationship, this just worked for me. I cannot stress how beautiful I found the art, and along with Hana wa Saku ka I plan on buying this series when I can.
So definitely read if you have time and want something different from the normal same-old same-old yaoi.
P.S. Don't read for the sex, but if you're finding it lacking a bit in both panel-time and description the series does get more explicit as it goes on longer. Although the scenes are not overtly graphic, there are a couple really tender ones where you can really see/get/understand the emotions of the characters that they are feeling at the time.