Any tangible difference between brake calipers comes down to quality of parts and finish. The real big difference in braking comes from the pads. That's not to say that the type of caliper and caliper design doesn't make a performance difference, but it isn't a big performance difference. I have used Ultegra, Dura Ace, Mavic SSC, Zero G (05 flavor)Ti, and now, Record Skeleton brakes. They are all very close in terms of performance....so close that it really doesn't matter. That said, I preferred the Dura Ace stoppers least of all for their performance. The Zero G stoppers are the ugliest of all and required the most attention: during setup getting the right cable length is crucial, and the ZG brakes do come uncentered more easily (like when transporting bikes or after removing/reinstalling a wheel). The best of those brakes, by a hair, no less, were, in a tie, the Mavics and the Record Skeleton.
The FSA brakes will probably perform similarly to those brakes, although I've heard that the finish on the FSA brakes is decidedly lacking. For those tight on money, the Mavic brakes are the way to go. Right now, I am completely chuffed with my Record Skeleton brakes.
As for the Mavic and Record brakes not having a QR: so what. There are plenty of people who use these brakes on Shimano systems. All that is required is that you fiddle with the barrel adjuster on the caliper to open the calipers up for wheel removal and reinstallation. It's not hard, and it doesn't take that much time.
I personally wouldn't buy anything from FSA since I'm really unimpressed by their QC and complete lack of design creativity. I used to have a set of FSA Carbon Team cranks, and I was thoroughly disgusted by the quality and durability of those cranks. Biggest waste of $300 in my life, they were.
As for the BC2A brakes.....some knowledgeable people have used 'em and found them to perform excellently. The finish on 'em was a bit dodgy, to some, but then they also haven't entered full production yet. There was a slight production delay.
Another set of brakes that is renowned for their performance is the set from M5. Everyone that has used them has said they performed very well, although some have complained that they provided little modulation. The finish on the M5 brakes is a concern to some. For me, I think the M5 brakes are the only brakes more ugly than the ZG brakes. The M5 stoppers are bulbous, and their "space frame" or "trussed" construction just does not look very tasty.