There is a feature I hope to see replicated for xenForo, one which I have seen on two forums, the first being Shawn Hogan's (aka "digitalpoint") Digital Point forum:
I have also seen it at the City-Data forum:
As you can see, in the first screen shot the forum names are click-able, whereas in the second it is the post counts that are click-able, but in either case clicking leads to the forums those posts were made in. Also, in both cases the number of posts the member made in each forum is listed. I wonder if this is a difficult feature to create.