I have both and tend to use them interchangably for dress functions, though the Kilkenny really goes best with the irish tartans or that have a lot of green and blue in them. I find, however, that while the bottle green goes over just as well for dress functions as the PC, it also works well for taking my lady out for a nice dinner in town. Kind of like a high quality suit. The PC, however, only works as formal dress. The black is just too much like a tux to be worn out on the town. IMHO.