Well if you look at what the pros are riding you see that many of them are avoiding the new DA(7900) and from my count only one rider used Di2 at Pairs Roubaix.
Personally I when with Campy SR, and I am very happy with it. I also wanted to mention that I heard the US rep talk about why campy went to 11 speed and according to him it was a matter of improving the shifting speed. The did this by bring the cogs closer together which in turn left space. The could have put a spacer but thought that most people would have preferred to have more cogs. It makes sense to me.
I have had SR for about 4 or 5 months now and in this limited time I have not found anything ware out any quicker then on a 10 speed. 4000km I'm guessing?
I will have to check the chain soon I'm thinking.
Someone asked what is the difference between last years and this years Campy? besides the 11 speed thing and the ceramics and bearings in the shifters and brakes the big thing is really the shifter/brake leavers, some people have commented that they don't like the look of them but they are very comfortable and I love them!! Most people that try them also feel the same way, but to each their own.
One last thing, for sure SR is nice and elegant (read bling) but for the money you wont go wrong with Chorus.