I don't know if it's the IT background in me or not, but I hate cables/wires hanging or dangling from anything.
I agree with the others that you wont gain anything in terms of performance but I am in the same boat. I hate the cables sticking out the side of my 5500 shifters. I have thought about buying a 5700 group several times for that reason only. I always talk myself out of pulling the trigger. My hate for the look of the cables never goes away though.