Good review.

Builder sounds very interesting. I use Thesis for a lot of my projects so I wonder what the major differences are though you seem to address some of those as with Thesis I need to install Thesis Openhook for access to the hooks available in Thesis.

It looks as if with Builder I wouldn't have to worry about that.

The one thing I would like to encourage with the dev team is to take the time to ensure accessibility of the theme with regard to the building options for users with disabilities.

I can sure help with that.