I actually really enjoy it, especially the two parts covered in the 2012 anime. SC became really formulaic, which made me sad.
I was probably mainly drawn into the series for the interesting settings that you don't usually find in anime, and just the wild, unpredictable story of the original two parts. Also, the classic rock referencing names. In the first two series they are all over the place, and it is hilarious. The series however is probably amongst the series I'm most shocked I actually like. It's overtly violent and very disturbing in places (the main villain in part 4 is... well, I don't know how to say it). I also very much hate the way that the author treats dogs, and I sincerely wish that would stop. (I'm not talking about Iggy, who is an actual character, and not some random dog killed off for shock factor)