Kodo
interesting you can only reply once to a post. not sure if that's an awesome idea or horrible idea
Jani Mustonen
I find myself wanting to chat a bit, but nesting answers infinitely doesn't seem like a nice thing to do.
Mark Dain
You can also delete replies, which is also awesome/terrible. I think it's for anti-spam purposes but I've only used it when I was giving out lobste.rs invites; people would reply with their email and once I invited, I'd delete it for privacy -- this is because Sublevel didn't have direct messages at the time