We put task checklists and bulletpoint jobs into comments, with updates as successive comments. This gives a nice timeline and lets us view rolling progress on the activity feed.
To do this, we have to either edit the previous comment, copy the contents over then amend the previous checklist, or quote previous comment and delete the remarkup (eurgh).
This is perfectly useable, but somewhat clunky and doesn't feel like a "clean" way of working.
It would be nice if, alongside "quote" we had a "copy" option on comments. The copy option would drop the text of the comment into the new comment box.