Upload & Sell: On
Yes. My 85L II focuses faster on my 1DX. This was a failry common comment on a recent thread on 1DX/5DIII. I can't remember which specific thread.
OTOH, I never had much problem or frustration with the 85L II AF performance on the 1DIII, 1DsIII and 1DIV, either. Maybe not quite as fast, but completely acceptable. It depends a lot on how you have AF set up. In low light, I gravitate towards the centre AF point, and that was just fine on the Mk III bodies. Finally, it depends a great deal on your expectations. It's no speed demon for initial acquisition, but generally it tracks quite well in AI Servo, if you can stay on target.