I'm getting my family setup up on XBOX but I am continually coming up against usability issues with the overall service. The most recent is around purchasing an XBOX Music Pass subscription for my wife.
Firstly, my wife, as an adult should be able to purchase her own, but she can't because she is a member of the Gold Family Pack. So I have to remove her from the family. Then she has to purchase the Music Pass, and now I believe we have to wait before re-adding her to the family. I am finding that the overall experience around Microsoft Accounts and XBOX account management is a problem.
If I had to summarise I would say that getting this stuff working seamlessly doesn't seem that important to Microsoft, almost as of XBOX revenue generation isn't that important.