Many of the sites Xponent produce are built upon modifications of themes dependent on Genesis. This way to work are very cost effective, if you can find a theme with the appropriate functionality and looks the client are asking for.
Some clients really need a theme made from ground up. This might be because of design ideas, or just the urge to own some originality, or the need for some functionality that must be designed in detail. When a customer ask for original design we still rely upon the Genesis Framework, here are a few links to original designed sites we made for customers.