One of my clients uses Headway, and it is pretty awesome.
Are you talking about when WP has an upgrade? If so, nothing changed for my client when we upgraded to the current version of WP.
Even though Headway has a very nice interface for changing colors, and way beyond, you can still apply your own custom styling to it if you wish by using the custom style sheet (
http://headwaythemes.com/documentati...te/custom-css/).
One thing of note is to make sure your host supports php5+, because Headway won't work with anything under version 5.