Performance has been more than tweaked with improved numbers in both ball speed and spin rate. Launch monitor testing bore this out in our apples-to-apples comparison between the Xtreme and its predecessor. A couple more MPH ball speed and a few hundred less RPM really add yards. In my case, the distance boost was easily 8-10 yards on average over Callaway golf drivers' previous driver offering.
The unsung hero in the RAZR Fit Xtreme package is Callaway's offering of the Aldila Trinity shaft as the stock shaft. This green monster has plenty of feel with a higher torque rating than many aftermarket shafts (Stiff 4.5 and Regular 5.4), yet sends the head into the ball very powerfully. Want more? Callaway also offers a low-spin Matrix Black Tie shaft for those who want something a little stouter.
There are many more engineering tweaks with the Xtreme, but one of my favorites relates to sound. The sound at impact is a solid "thwack!" that moves best golf clubs off a trend toward "plastic-y," dull-sounding drivers.