Reading https://news.ycombinator.com/item?id=12907201 I was really annoyed by the fact that it takes ~5secs to "Collapse" any of the Replies.
It left me wondering: is it possible at all to make it better? Is it the result of lousy programming? Or is the thread just too big and as such there's not much to do?
http://i.imgur.com/xiPcxBd.gifv
If my guess is correct, it could probably be changed to optimistically collapse.