(I'm here because the volatility on Reddit is too much for me).
On the other hand, checkout http://www.reddit.com/r/depthhub. That subreddit flags many of the deepest, most insightful comments on reddit and is a fascinating trove of information about all sorts of interesting subjects.
For example, here's a brilliant comment that compares and contracts Aldous Huxley's "Brave New World" and George Orwell's "1984" (both excellent books, I might add): http://www.reddit.com/r/books/comments/1hhrpk/huxley_vs_orwe...
In a sense, Reddit can tend towards a Brave New World style of information by drowning us in so much information, much of which is false or inane, that we can lose sight of what's important, but as a source of entertainment, it's often terrific.
The 'comment management system' in Slashdot makes the best comments 'bubble up to the top' because they obtain higher 'scores'.
Why is Reddit's 'comment management system' so much more primitive than Slashdot's?
Reddit is more inclusive of society than slashdot and is more likely to represent everyone along the bell curve.
Lately, I've been hanging out on /. for that very reason. The topics and discussions are higher quality than HN IMO and the site is more configurable for the user.