Upload & Sell: On
I'm mostly playing with it on the new USB dock and Optimization Pro software -- I can say that if you get the new lens, then absolutely, definitely get the dock and software. It's way too cool for school.
Just playing with the AF Speed customization (for speed, don't ask me about accuracy) near to infinity focusing is 0.92 seconds in standard mode, 1.1 seconds in 'smooth' mode, and 0.65 seconds in 'fast mode'.
Plus you can microfocus adjust for 4 different focusing distances at 4 different zoom settings. There's an OS customization, too, but reading what they describe the different settings as, I have no idea what they mean.
But you get to set the C1 and C2 switches to custom settings of AF speed and OS type. So for AF speed at least you could have C1 as fast and C2 as 'smooth'. I have no idea, and they don't say, whether smooth might be more accurate in difficult conditions, but it would seem logical it would.