I own both the X-Lite Aero and the Rolf Prima Vigors. Here's the difference:

Aeros are 30 mm deep, Vigors are 34mm.
Aeros weigh 1710 gms/set, Vigors, 1455
Aeros have ? hubs, Vigors are White Industries, which are incredible.
Aeros are $749 msrp and can be purchased for $675-700, Vigors are $849 msrp and can be purchased for $750-800.

Both were designed by Rolf using his patented paired spoke technology. Bontrager inherited many of the patents Rolf sold to Trek when he worked there.

Both are great wheels, the Vigors being the next generation to the Aeros.

55/Rad