I dislike the right side persistent navigation bar. It takes up considerable room and it makes the page unbalanced as you scroll down. I prefer the content to take up the full width and to be centered. When you scroll down on a long page, the navigation scrolls out of view and content is off center. When I code, I prefer to designate the majority of my screen to the code. The right navigation column seems like wasted space.
This was my first impression too. Especially when viewing the Readme for a project it's much narrower and feels more squashed. They seem to of focused on the project owner use case and ignored the project user use case.
