I appreciate the feedback provided.

The bike is at my LBS right now. Just got home. And I talked to one of the very experienced techs there. Actually two of them including the one that assembled the bike. It seems that 2012 (and maybe older) models of the Specialized Roubaix were built with electronic shifters in mind, but they then realized they were going to be selling a lot of mechanical shifters despite their dreams. Problem with that is that the frame apparently has a point or two that basically somewhat crimps the RD cable inside the frame, and while electronic shifting can deal with that, mechanical shifters are not dealing with it well. So Specialized offered up a solution to this problem, but the LBS has apparently come up with an even better solution. Bottom line is it basically frees up the movement of the cable inside the frame work and results in smooth and consistent shifting. They said the short cable length at the RD is not the issue. They have already done this on about 20 bikes with perfect results to date. Mine will be 21. I'll be picking it up tomorrow.

But thanks again for any feedback.

For the record, the 2012 bike came with an Ultegra 11-28 cassette on DT Swiss 3.0's. I have Mavics on it now with the same cassette (not moved, but another one), but each wheelset and cassette has the exact same performance characteristics. Rode them both. And it also came with a Shimano 105 chain. Never understood why it came with a 105 chain while everything else is Ultegra, but that's how it shipped. Maybe they were trying to save $10 ? I see where new releases are now coming with 105 cassettes on DT Swiss 4.0's and Tiagra chains. Go figure.