My perception is that submission quality is roughly the same, but average comment quality has been dropping. Maybe the solution is to make comments work more like submissions, e.g. new top-level comments start out dead and need two upvotes before they go live. This is essentially how all new stories start out, and it seems to be working reasonably well.<p>Also, part of the issue with scaling is that there are some types of comments that are fine to post when the userbase is small, but that aren't ok to post as the userbase grows-- even if they add value in some way. So the problem isn't just coming from new users posting bad comments, it's coming from old users posting the same comments. So maybe some sort of radical experiment to try to refocus the discussions wouldn't be such a bad idea, at least to see how it goes.