MD-11/MD-10 flaps up takeoffs!
We MD-11 bubbas went through the same drill ... after hundreds of takeoffs with the new procedure, I STILL DO NOT LIKE IT. At the very least, it results in a MUCH higher rotation speeds (MUCH less stop margin!).
IF we run even 1 airplane off the end of a runway during a rejected takeoff we will have lost all of the benefit of the perceived fuel savings.