Steve Pearson at Wills Wing states:

UVM sailcloth is very expensive, but has far greater UV stability than conventional Mylar film like smoke or titanium dioxide. The upgrade cost for it is $300 and is standard on the T2C (although pilots can choose standard Mylar if they like.)

The 12mm x .04mm aluminum battens are lighter and have comparable stiffness to carbon battens.

7075 aluminum is used on the airframe including sprogs except for the control bar.

Custom colors available as an option at $150 for the T2, but at no cost on the T2C.

Any additional thoughts from Kraig or Deb or Urs?