In a clean install, no migration of prior settings, there are issues with the Create Roof tool.
You have to initiate the roof styles with at least one. When you open it to edit the default component it has no name. Adding a name and using it after that it seems to work.
Opening a 2015 file, doing the same, initiating a roof style, then applying that style to the existing roof does NOT resolve the problem with eaves. Some are left as is with double mitre, while other are randomly change to just a vertical cut.
I can not move forward to 2016 if it means creating unnecessary work, and obviously can't be trusted because of it's inconsistent behaviour.
I wish they had left the original tool as a basic Roof Creation tool, and made a new separate one for roofs with components. It's a nice idea, would be very useful, but as is is not useable.
I'm trying to avoid a negative tone, but I am very annoyed over the time I wasted on this issue.