Never heard of lesswrong, but it looks cool at first glance.

I've never been a fan of reddit. My experience with reading it is that everyone tries too hard to be a smartass, and rarely contributes to the discussion/thread. Although, I might have visited the "wrong" subreddits

In general, any subreddit that hits the default front page is garbage. If you can find a smaller, niche subreddit for something that interests you, there's usually more focus and better moderation.