Sometimes in the hnews comments I'll ask a question and normally the answers I get back are pretty good even though my comment is rarely popular. Most recently I asked about some subtlety in the Meltdown vulnerability.

It would be cool in addition to "comments", there was a Q&A section. I find I mostly click on the comments to get a more nuanced understanding of an article only to find a 20-commeny deep flame war about something unrelated.