6L80 will handle a lot of abuse, I logged well over a 100 runs on my 2010 CC shifting so hard it would do 1, 2 and 3rd gear scratches. I gave that truck to my Daughter for graduation and she is still driving it today with out any problems. I believe there is about 19,000 miles on it now, maybe more.

Allen has a video on here some where of it shifting, I will see if I can find it.