I like the Specialized Tarmac in SWorks trim for efficiency. As a climbing bike I can't think of a better production frame. I don't have one though I may be getting an SL4 soon. It's not the bike that makes me go but every bit helps. I agree the lower trimline groupsets shift quite well. I do believe that DA does have a better tactile feel, smoother, with slightly less effort required to activate. But as far as moving the chain, there isn't too much between the low end and the fancy stuff.

I was most impressed with deep carbon wheels I borrowed for a century ride. I'd love to have a set though I find the cost prohibitive.