I loved overture!!! Anyone who reads this review and likes rozen maiden must watch it! The story was very good though I did think it would be a little longer, that's my only qualm. The relationship between Shinku and Suigintou is one everyone must know about. The art was pretty good too, the same as the other 2 seasons. I loved the opening! One of my favorite anime openings right now! :) It's very...beautiful. Sadly I don't usually pay much attention to anime endings so I have nothing to say about the ending. The characters were wonderful. As usual, I loved Shinku though sheis different from how she is the other 2 seasons. More cold and harsh.
I had a love/hate thing for Suigintou, at first she seemed quite sweet and determined but towards the end overture I think she goes too far. You will have to watch it to know what I mean, I'm not gonna spoil it for you. ;)

My overall enjoyment was indeed a 10! The only thing is it left me craving for more, a third season of rozen maiden is a must!