Shifting feel is part of a package of components -- shifters, cable and housing, derailleur, routing. I haven't been able to feel much difference between my various Shimano 600, 105, Ultegra and Dura Ace derailleurs. But the shifters are different for each, a mix of brifters, downtube shifters and bar-end aero bar shifters. The Dura Ace 7800 RD I have for one bike is nice but not that much different from the others.

Dura Ace compatibility info.