I'm also concerned because of the hive mind effect. Just because something is popular, doesn't mean it's quality. You attract more flies with honey than you do with vinegar, but you get a LOT more with a steaming turd. And sure, the turd is popular, but is it good eats?
And I find using the karma total is a poor choice. Reaching 1000 karma isn't that difficult, nor is it an indication of quality, it can be an indication of the age of an account, or the prolific nature of the commenter. Someones ratio is a far better way to ensure that the individuals deciding are also quality posters. A single troll with an account in the 1000+ can chose to use that to green light his other accounts, and other trolls.
I look forward to being proven wrong though.