The system mostly works. Admins are available to moderate the exception cases, and offer policy guidance as needed. There are a few number tweaks I would personally make if they weren't so ingrained into the system, but they mainly deal with the instaguru noob phenomenon (or instasubscholar posters who later become long term additions to the site) both of which we are able to adjust as needed already.
Aside from a continued, concerted effort by a few people, once you hit over 10,000 posts it really takes an admin to make a significant rapid change in karma score, which is why we usually leave the ratings alone of people that high up. Since most of the people here know better than to karma camp people. Everything else works fairly well. Spammers are still a problem, but it's difficult to detect the difference between a spammer and someone with just a non native grasp of English sometimes. We have anti-spam limits in place, that vary by geographic location and content, which mostly work well. There is one particular set of spammers from india that has a whole damned ISP worth of addresses to cycle through and have managed to locate most of our anti spam defenses and program their attacks around them in waves of multiple accounts from multiple geographically collocated IP addresses that all just happen to hit at the exact same time. Short of just banning India outright (which I am not opposed to personally) the way they are attacking with multiple non consecutive ranges, ID's and e-mail signups which are created seconds before the spam begins makes it next to impossible to stop them quickly. Usually the automatic defenses kick in before they hit 15 topics, but in a 50 topic view page with 7 different attacks hitting it at once, it doesn't take much to cause problems. We are working to improve the topic display subsystem so that a pile of banned topics doesn't result in an empty display, and we are working on making it easier to remove all posts made by a spammer from existence. The current process right now is 3 clicks per topic to remove, and limited to a select few admins to prevent the temptation to make an occasional post mysteriously cease to exist with no records (technically there still is one, but only if someone goes and looks for it)
We don't want to implement Captcha or similar things, they kill posting. Someone is manually creating the new user accounts to spam with right beforehand, so a captcha on account creation might not work and would just annoy other users. They have enough acocunts and IP's that lowering the post rate limiter to intercept spam would just lock out legitimate newbies and **** them off rather than reducing spam overall. The spam topics they are using are so stupid that blocking them all would require banning every variant of the word "kitchen" "love" "magic" and "ID" some of which are kind of important to a MMO themed gaming forum. Especially that magic one. So short of nuking India, banning their entire IP range, or someone actually shooting the spammers in the knee repeatedly, we remain under siege. The only saving grace is it's not just us, and other forums out there aren't handling it as well as our system is, which given how easy it is for the damned spammers to knock all the posts off our front page is suprising. We're working on it though.