Did this help?
I'd like to see some numbers on the actual number of questions that were closed by the community alone, but I know it's significantly higher than it was for 5 close votes (I can likely count on one hand the number of 5 vote closures we've had in the last few months.
Did it hurt?
No. It kept things a bit neater, eliminating things like our ever-present web development questions, and it allowed the "community" (our small cadre of consistent users, at any rate) to make decisions rather than me.
Did it make you more interested in reviewing? Less?
It took some reviewing off of my shoulders, so it was nice. It seemed to bring down the number of posts in the queue significantly, but only for a short time.
Was three the right number?
Three was a perfect number. Enough to create checks and balances, but enough that different people could participate and feel like they were making a difference.
Should it be permanent?
I think that this experiment (and the election itself) brought up some important issues. I don't think that close voting is our overall problem as much as participation. The fact that only one user besides myself weighed in on this question is disappointing. Forty-four other people viewed it, and I'd really like to know how they felt as well, even if it's just "I'm not inclined to increase my participation to such a level".