I have to agree with Ritardando about the drummers. I think Kyoichi is a good drummer, but Masuke seems a little more subtle, dynamic, and agile.
I also think Koichi is an excellent guitarist, and it amazes me as someone who used to mess around with the guitar how many different songs and styles he has to learn for these marathon lives. However, his timing seems just slightly loose, and I don’t think most of his solos add much to the songs, especially live. That actually might be more Yuki’s fault for not giving him adequate direction. I think she should compose the guitar solos to make sure they integrate melodically with the rest of the songs (although some of the solos do that, like I Swear).