Well actually I don't know about other users but for me personally, I use ~snip to trim when I'm making a general or rather a summarised reply to what the person has previously said. The point is I'm either contributing or supporting or against your opinion when I quote. Let's assume you make 3 points and I agree with them and I just want to add to it then I'll use snip like I did here.

However if I for example agree disagree with 2 of those points, when I'm replying I'll quote each point separately and reply to them separately.