The absence of spam and drastically off topic material is a huge plus for the site. We've pretty much stayed on topic, and I think Paul has said they have human moderators whacking bad submissions or comments. The voting helps with that also of course.
The amount of spam they've been killing has actually been substantial for the past week. (Mostly the same couple spammers; I don't know why they haven't banned their IPs yet). I've been keeping showdead turned on because I'm curious about seeing how the situation evolves, but once spam reaches about double its current volume I'm going to turn it off because it'll be too annoying.
Edit: Maybe they've banned them now; the new queue is currently clean.
I wish the Reddits had been doing this. We ran into some bizarre impeachment behavior a few weeks ago. I think they're proud of running an open and market-driven site, but sometimes that can go wrong. Shirky's essay at http://shirky.com/writings/group_enemy.html sort of describes this.
