I found this manga to be quite enjoyable. It's different, as far as Blood+ goes, but still very good. The style of the art is very nice, actually a bit cute at times. The plot is interesting and suspensful while retaining a comical side.
The things that take place in this manga are unlike anything even suggested in the anime, so I think this is a cool story, like another episode!
Overall, it's very good, I definitley suggest taking the time to read it if you're a Blood+ fan!