I created a new forum sidebar in which we group new replies by post instead of just listing it by post title. The advantage is that you get a better picture how old the posts are and that there is less to read since it does not repeat the post title for every reply.
The disadvantage is that you have it a bit harder to find the latest replies across several posts since they will be further down in the list.
There is an open question if we should limit the list. Currently I list the latest 20 posts and their replies.