I had all but decided on the Bridgestone Potenza Pole Positions (at $177 a pop) but a friend recommended the Kumhos. Tirerack did a test between Continental, Kumho, Yokohama, and Sumitro UHP tires. Kumho came in 3rd overall and Yokohama W4s came in 1st.
I made the mistake of getting the Avon M550s when they first came out and have paide for it over the last 20k miles with loud tires. Due to that, I'm not confident on grabbing a brand new tire.
I'm leaning toward the Yokohama V4S, which is just HP (not UHP). This should result in a slightly cushier and quiet ride (which is what I want) without sacrificing too much performance.