Starting off with the bad. Umineko didn't really end, it left with an uncomplete ending that ends halfway through the game series. This makes less sense then it would have for Higurashi, Ryukishi07's other famous work, because Umineko is more straight forward than Higurashi was as a game series. I have to say that that's where the story was lacking, other than that, it was a very good adaptation of the original Umineko game franchise up until the 4th game.
The good things do far out number the bad things though. When it comes to character development, you have all these family members that are all wanting control over the family's inheritance and mansion. A couple are in it for financial gain, one of them wants to gain the acceptance of her father, and the other just wants to screw over the rest of the family. When it comes down to actual character development, the series takes on the development of Rosa and Eva as two very close sisters, but at the same time hating each other. This is all without spoiling anything in the series, I can promise you that. Then you have the Youth in the family who just want their parents to get along and stop fighting over the inheritance. Later on you even get character development for characters that were really only supporting characters for the first part of the series. Moving on to the story, I wouldn't expect less from Ryukishi07, he really takes certain times to blow your mind in this series and create characters that you can just despise while telling a story, the story was awesome. I love Ryukishi's art style in anime so that was a highlight for me and the soundtrack was just amazing. I have to say that I really enjoyed watching this series.
Final Verdict:
You should give it a chance and don't let the ending bother you too much.
