I would think 2ndS realizes the benefits of return of serves wth 2hbh, and is not set on swithing completley over to 2hbh until he sees the benefits of 2hbh during rallies.
Question is also out on 2hbh for volleys, since GeneMayer, FrewMcMillian, JimmyConnors (when he was getting to No.1) and now Bartoli can absolutely CRUSH waist high volleys for clean winners....
I like the 2hbh volleys myself. My 3rd thru 5th year of tennis, exclusively 1hbh if I could reach the ball. 1hbh on forehand volleys, though.