Just to put in perspective, I calculated the energy to be absorbed with a 2,000 pound vehicle in a stop from 80 mph.  It comes out to 214,000 ft-lb per brake, so it is right in the neighborhood of what is claimed for either of the brakes.  What isn't said is the initial and final rotor temperature assumed.  The capacity of a brake is directly related to the mass of the rotor - this can't be compromised.  Of course, the hub of the rotor isn't part of the calculation and on a conventional brake that mass is essentially wasted.  And there are two factors to consider:  Specific torque (ft-lb torque/psi) is proportional to the friction coefficient, effective diameter and piston area.  Just rating a "torque capacity" without giving the pressure required to get that torque doesn't tell me much.  Energy capacity (ft-lb) is proportional to the temperature rise, rotor mass and rotor specific heat.  When someone talks about "stopping power" I'm not sure what is meant.  Any brake/master cylinder combination should have the ability to lock up the wheels with a reasonable pedal effort, but that has nothing to do with the energy capacity.

According to the posted numbers the Beringer brake will end up at a higher temperature after a given stop, with a 24% higher temperature rise.  Would the higher temperature result in fade at the end of a rejected takeoff?  Does that equate to a shorter pad life?  Maybe, but is that a reasonable trade-off for the lighter weight?  Probably - in my opinion, anyway.  The Beringer brake will require 12% more pedal effort for a given torque assuming both were rated at the same pressure.  Is that enough to be important?  Does the ligher weight justify the higher price?  Only the buyer knows that.

Gary