I strung Sock's frames earlier this year at a futures event, and then again at the Cincinatti Masters 1000. Both times he strung at 38lbs.
At the futures, he was using Pro Hurricane Tour. At Cincy, he was using Pro Hurricane, and then purchased a few reels of Alu Power after trying it out, and deciding to switch.
Head Stringer @ the LTC, Babolat Star 4 Stringer