10 and 11 speed RDs do have a slightly different actuation ratio, so they are not totally interchangeable. The 11 speed model will move further for a given amount of cable pull. The difference is not great, but the 11 speed RD will work better on a 10 speed drivetrain than the opposite mismatch because it slightly over shifts, while the 10 speed RD undershifts, if used on an 11 speed drivetrain. I've posted before how to modify the 10 speed cable clamp bolt so it will work with 11 speed.

Here's the cheapest 11 speed RD. http://www.ribblecycles.co.uk/sp/roa...RR922000000000

I've routed all of my shift cables around the back of the bars, but I quickly roll the housing under the bar, so it exits near the center, right behind the brake cable housing. The bars I use have too sharp a bend for the front routing.

The new repair kit, EC-CE110 may solve the vague right finger click, but I've still not been able to verify that.

I didn't care for the vague right finger click either, so I converted my last 10 speed bike to 11 speed. I got the parts to convert the Centaur shifter from a wreck damaged Record shifter, added the cassette and chain. I used Shimano cable housing with a new Campy cable.