My stumbling block with ghpages is the workflow. I have not found a good way to work with the project in the master branch and then my docs/web-content in the ghpages branch. A lot of time all I really need to do is take something from my master/working branch and transmogrify it and dump the output to ghpages. Maybe its something about my git-fu? Or maybe most people's ghpages is less dependent/tied-to what is in their master branch.
Am I missing something obvious?