From 2009 GOLF Magazine Buyer's Guide:
It's for: Better players to 15-handicappers
Dan Stone, VP of R&D: "The composite crown allows us to lower the center of gravity (CG) without increasing backspin. 909 DComp delivers high launch with low to mid spin."
How it works: The 460cc, multi-material head (titanium body, composite crown) is stretched longest from face to rear among 909 drivers. It also has the deepest CG, highest MOI and belts out the highest ball flight with the most backspin. Expect more help on misses, too. A factory-installed swingweight screw (2, 7 or 12 grams) is used to match head weight with your preferred shaft. Comes with the Titleist Matrix Ozik XCon shaft.