In its latest iteration, the British Army Rumour Service (arrse.co.uk) introduced a set of buttons visible for each post. Categories include: Like; Dislike; Funny; Informative; Bull....: Old [news/information].

That may be a bit excessive, and as I rarely go there these days I'm not quite sure how well its working. But certainly the option of "Helpful" and "Like" seem a possible benefit when trawling through long/complex Threads.

At the very least it might reduce the " ^ +1 " posts, which then often lead to a side-discussion or similar " ^ " posts.