Thank you for the article, Brian, and and the reinforcement, Bob.
Blanket rules of thumb, with no design direction, are one of the many reasons Alpharetta and towns like it are text book cases for suburban sprawl.
Personally speaking, I am a 42 year old professional male with a wife and 2 boys and have absolutely no desire to be a slave to a McMansion estate and Briggs & Stratton life style. The term "Multi-family" is too broad of a term to have such a generalized ratio given to it.
I welcome the Avalon project to give a better variety and diversity to our community.