I've used two FSA cranksets on my bikes in the past - '03 FSA Carbon Pro Team Issue ISIS w/ Platinum Pro BB and '05 FSA Gossamer w/ MegaExo BB. Both worked fine, I experienced no functional problems with either. Although I will say that cosmetically, the carbon finish on the Team Issue did not hold up well. The clear coat was prone to scratches and also chipped off so the crankset looked like hell after two seasons. Perhaps this is "normal" with carbon cranksets? I don't know, it was my first and only carbon crankset. On the Gossamer, the painted finish was also prone to scratching.
I have since upgraded to a 7800 Dura-Ace crankset and BB. I found ceramic bearings for the D-A BB through work and replaced them. Love the D-A. Great feel, cool looks, super stiff, flawless shifting and on closer inspection, the D-A has a much better finish and machining than the FSA's. Just my personal experience with the two brands.