I think what I appreciate most about Aida Saki is that she really manages to make you care about all the characters. I also like that her yakuza characters aren't... well, they are certainly written in a way that makes them likable, so to say they aren't glorified isn't quite right. But they also definitely make their hands dirty. As strange as that sounds, I prefer it that way.
I love Hatori the best, he's easily my favourite character of this series. I think she could have digged a little deeper at some points, but still, this was very satisfying.