As a someone who has been a reddit default moderator for 6+ years (I help out in more than 1 default subreddit), I'd say they're still small time. It's so bad over on reddit that even with a fully active staff, we have to utilize bots to automate much of the work. Without those bots, it would be impossible to have a community at the sizes we're talking. We simply wouldn't exist.
He overstates how bad the job is because they've never experienced "true" bad... The author should see if he could intern for a month on one of reddit's busier subreddits. If he asks, I'd be more than willing to give him an inside peek into one of our subreddits. Weekly 4chan raids, intra-subreddit brigades, people (spammers, SEO types, marketers, etc) trying to game us to reach the front page for profit, and then to add on top of that, we have all the same trolls and racists and psychopaths theguardian has to deal with. That's actually not true, they're not the same, there are more of them on reddit. Many, many more.
I know this isn't a competition, but I look at the average comment there and I can get a feel for what moderating there must be like. And I have to say, it looks like paradise compared to reddit. It would be a vacation and even that would probably be an understatement. Though, TheGuardian is the 128th largest website in the world while reddit is 28th (9th largest in the U.S). That's quite the discrepancy.