I thought this might be of some interest to the dudes who "hit up on the driver..."
With the driver, the designers were able to move weight internally to really match the head's center of gravity to my swing. Normally, the weight in the driver is back and low, which fits most average swings. It doesn't fit my swing, because I make a slightly descending blow at impact. Callaway was able to move a little of the weight forward and slightly higher, and that keeps the clubhead level through impact. My equipment changes were really about taking my game to a new level. I learned a lot about equipment and making my misses better, and it has made a huge difference in my game.
Source: http://www.golfdigest.com/equipment/mybag/index.ssf?/equipment/mybag/gd200506mickelsonbag.html
With the driver, the designers were able to move weight internally to really match the head's center of gravity to my swing. Normally, the weight in the driver is back and low, which fits most average swings. It doesn't fit my swing, because I make a slightly descending blow at impact. Callaway was able to move a little of the weight forward and slightly higher, and that keeps the clubhead level through impact. My equipment changes were really about taking my game to a new level. I learned a lot about equipment and making my misses better, and it has made a huge difference in my game.
Source: http://www.golfdigest.com/equipment/mybag/index.ssf?/equipment/mybag/gd200506mickelsonbag.html