Electronic & Hydraulic Shifting (Di2, Ui2, customisations)

SRAM Red downshift quicker than both EPS and Di2 something like 1.25 second compare to campag/Di2 1.8-2second.

Downshift what?

"If absolute shift quality is the primary concern, electronic wins out. Di2’s front shifting is still the best available, by a pretty decent margin, and the rear shifting of all four electronic groups is perhaps best described as impeccably predictable. It simply works, every time. No fiddling, no adjusting; just set and forget.

Campagnolo EPS front shifting sits just behind Di2, followed by the new SRAM Red group, Shimano 7900, and Campagnolo Record. With the update to Red, the front shifting quality of the top three mechanical groups is now so tightly packed that it becomes a useless metric, except against the still superior electronic groups.

Rear shifting isn’t so easy to sort. A mechanical system with properly routed and uncontaminated cables and housing can match any of the electronic groups. Red feels like the quickest shifter of the bunch, largely thanks to its short lever throw. But if you time a shift from its actual initiation, or when the cable is taken in or let out, all the top groups end up nearly identical. (And yes, I wasted an afternoon doing this with a video camera.) So, rear shifting is essentially a draw, except that electronic systems will never run into contamination issues."

http://velonews.competitor.com/2012/02/bikes-and-tech/the-torqued-wrench-enter-the-thunderdome_206988