I really like the way you've got the tags (3D, etc.) working, with the "filtering" function at the top of the forum.
Just for the heck of it, I quickly browsed through all the 3D pages. There are 449 threads, which pleasantly surprised me, and this is activity that will continue to grow. So then I was left wondering why the decision not to just keep it as its own sub-forum.
It also occurred to me (only half seriously) that taking the tag functionality to its extreme, there would theoretically have to be only one humongous forum. with every thread tagged and able to be filtered on. That's silly, of course. But it still brings up the question of where the lines get drawn. Just curious, mostly.
I do look forward to having the missing buttons such as RAH's available as well.
The filtering icons will be coming and going this weekend as we are working on them. Regarding 3D and other tags, its not just the number of threads, but the amount of regular activity too as well as other factors. Sometimes segregating things works well, other times it doesn't and those areas end up losing traffic. We worked with some forum and UI experts to figure out what the best forum structure would be. In the past its been fairly knee-jerk, so we wanted to step back and take a fresh perspective. These changes have been in the works for a while, we just thought it made sense to do it at the same time we migrated the platform.