From Golf Magazine (March, 2011)

IT'S FOR: Tour level players and skilled amateurs.

SKINNY: The 4-piece ball, has a story all its own. A lightweight rubber-less core (made of polymer) makes the mantle and cover 10 percent heavier. As a result, drives launch with less spin (100-200 rpm) but maintain spin longer for better carry and control. The 20XI-S (replaces One Tour) has Nike's softest urethane cover ever for max spin and feel on approach shots; the 20XI-X (replaces One Tour D) has a firmer cover for lower spin and more length.