In my opinion, there's a difference between quality post and merited posts. If you ask for what quality posys are, I can't give a definite answer since the forum didn't define what quality posts are.
Quality can not be used to quantify a post it either a post is good or bad, there is nothing like a quality post, the whole merits thing, is just how people react in their way since we do not have the React and Likes button merits is the only way people react, I have seen some low post being merited and somewhat seems to be a good post being ignored.