It appears that admin sections/beta sections (if they exist which I assume they do) are not visible. However you can tell there's something there because it throws out a different 404 response (comes up with a blank rather than just redirecting to the main forum)
Nothing that really matters but just something to know.
The patch test forum is hidden but visible if you know the url - it's intentional. For archival purposes and to prevent sudden 404's.
Administrative forums now behave like non-existent forums for those who cannot visit them.
There is no option to search for posts made by username on threads. For example if I wanted to find my own posts in this thread I could just search for them on the old forum (search from thread in the thread tools) but now there is no way other than to manually search. I sometimes use that to search my own username in a thread just to see what I've written earlier so I don't write the same thing twice...