The Inheritance cycle

Eragon, Eldest and Brisingr were really good books while Inheritance was a little bit of a let down. It lost many of the finer aspects of the first three and in general the ending was really odd , I mean if you could live forever would you have left your loved ones so soon? I wouldn't I'd stay until my cousin was a old man and his wife a withered crone and then I would leave and most likely never return.
I just think he left Alagaesia too soon.