I honestly can't think of a single way HN's software is superior to reddit's from my standpoint (as a user), so I'm curious -- what is it you like better about it?
I agree that Reddit has a terrible user interface (IMO, obviously) and it's amazing it has the traction it does. Of course we could also say the same thing about the vast majority of forum software, too. Apparently human communities are very, very good at getting software to fit their social needs even when the UI is suboptimal.