I think in general people give too much credit to the shifters for the "smoothness" of the shifting. The shifter just pulls and releases cable. How well the cables are installed and routed, as well as the adjustment of the deraillers makes far more difference. The front shifting is also going to be greatly affected by the chainrings, the profiling of the teeth, the ramps and pins, etc.

Now, how many people are really running a completely homogenous group? Is that crank really 105 or some FSA thing? Etc, etc, etc...