To upgrade my crankset from SRAM Rival to FSA K Force Light Carbon (the new one with ceramic BB). Is it worth it? Already upgraded wheels and looking to drop some more rotational weight on the bike. Do I need to spend $600?? I know a Dura Ace crank would be much better than what I have and cheaper than the FSA, but it would not look good. Is it worth the money to go for the FSA with ceramic or would the model just below (SL K)serve me just as well? What do you think?