I will not strongly favor a notification mechanism, I like hn because I consume this website and not the opposite. Notifications kind of create an urge to respond quickly which may not be necessary in most cases. However, adding optional setting in profile page would respect both who want to be notified and those who don't.
I go to HN because it isn't just a random news site with laypeople commenting on tech they don't understand; it's an aggregated news site with commentary from the exact people I want that commentary from. I've found myself not bothering to ask questions I want to ask because no one will see it after a certain amount of time despite the fact that threads that are over a year old end up on the front page.
Additionally, it sucks having to click two times (User > Comments) just to see if someone's responded every few minutes/hours. I've got better things to do. Notifications are a passive feature; you can choose to ignore them or turn them off, but I think they are vital to sites that tout their userbase and the intelligence therein. You could almost say Reddit's success can be hinged on the orangereds.
