I like the idea of community. In general, I follow similar guidelines in my upvotes and my occasional downvotes. On an individual basis I also upvote things that I find interesting or amusing or that teach me something new. I admit that I don't always weigh everything with a higher purpose of community benefit in mind.
I think that the community at Perl Monks is very diverse. There's a vast range of experience, competency and styles represented here, from newbie dabblers to professional programmers. It could be chaotic. But it seems to me that it all evens out through the voting. Whatever standard people individually apply to a node, they usually seem to agree on what is very good and what's not. I've never seen something that I consider a Great Node ever appear in the "worst nodes of the day" or seen a Terrible Node get tremendous upvotes. The cream rises, the sludge settles to the bottom and most everything else sits moderately in between, helping some, boring others but all in all providing the energy that keeps this site alive.