I'm not too surprised, I know we still have 6 English ones left to go, I'm glad that the series will get true closure, and I'm happy that Rikudou will finally be able to move on with his life and try out new things, but this still makes me kind of sad. Really sad, in fact. I mean, every good story needs to end and deserves to end, but I wish it wouldn't. Perhaps he'll do some (clean) doujins or special chapters in the future to continue the madness, if only briefly. But probably not.
I love how it's ending at 27 volumes, though. Seems sort of like an in-joke; an "I can one-up the anime version one last time!" statement, in a way.