The goal behind K5 is to be able to scale beyond the limitations of other forums, notably Slashdot. Currently K5 traffic is about 10% of its big brother. All told, the comment quality level is pretty good.
But there are [link|http://www.usemod.com/cgi-bin/mb.pl?KuroshinSubmissionQueue|significant problems with the K5 submission queue]. The site also needs filters (eg: don't display posts below n score (with other variants). I consider the site moderately successful -- the portions I've had a hand in, namely the comment moderation, work well -- good content is promoted, bad content sinks, middlin' stuff gets a middlin' score, very unlike Slashdot. Moreover, there are reasonably few trolls and mindless posts -- levels now at a few per day, but they tend to weed out quickly. Submissions more or less suck.
WRT Carnage4Life, he's been part of the K5 community since September, 2000, if not before. I might note we've got [link|http://z.iwethey.org/forums/render/user?userid=23|our own Microsoft mole] here. C4L's not made a secret of his affiliations, though he could well have been more open about them. The commentary in his article was reasonably balanced last I checked, and he's got the ghost of a point.