Well let me put it this way, I just got 140 shots in a row with the 5D3+24-70 II at f/2.8 under indoor lighting 100% in focus.
(by far the best result I've ever had from any lens+body combo)
Also very happy. 5DIII + 24-70 II is giving some great results.
This one is at ISO 1250 - 1/125s @ f/5, 600EX-RT to camera left in a softbox, fired using an ST-E3-RT. No real post processing - just loaded into LR, cropped and exposure moved back to the left (-0.45EV in lightroom as flash was set +0.3EV).
Plus a 100% crop for the pixel peepers.