Approaching 3000 days on HN. The things I notice most:
* increase in users has increased the churn rate of new submissions.
* the new page is dead because of the submission rate. good stories disappear off the stack quickly.
* the up-click is not a good indicator of story quality. I now see stories with up to 80 votes sans one comment. I used to read the comments BEFORE the post. This has now changed because of limited comments.
* the rate of high vote submission decay, means some good stories are lost as the HN crowd chew over some interesting post(s).
* also interesting to see users comment/post ratio. A lot of ppl have limited or no posts yet they comment. If you look at my post profile, in the last 60 days I've posted 100 posts. Approx 1:25 hit > 100. It would be interesting to see how this has changed over time. cf: https://news.ycombinator.com/submitted?id=bootload&next=9025...
The biggest problem is the dilution of good posts/actual posts. Slow the rate of posts and might influence the quality of posts.