I just got my bike serviced at The Missing Link, Berkeley's co-op run bike shop. It was one of the wisest decisions I've made in recent history. My bike is easier to pedal, though that wasn't terribly obvious on the 5 blocks I rode it so far. What was most striking was the way it shifts perfectly now. It used to click a bit, and have trouble getting into certain gears. Now it changes gears like a dream! I'm delighted.