Patriot

They're both great. I have the FSA Superlight, which, if used with the FSA Platinum Pro Ti BB, is a bit lighter than the new DA crank setup. The new DA though, does have the outboard bearings, which can now also be had in the FSA line.
I think at that level, it is just a matter of preference. I test rode a bike with the new DA crank last year, and honestly didn't notice a differance from my Superlight. Of course, it is hard to tell when the frames were diffrant, since all frames flex differantly.

But as far as cranks go, they are both very stiff, and have little troubles. Just depends on whether you want alloy, or carbon. I know one fella who sells components online, and he has both, and says he prefers the carbon. He says it seems stiffer for some reason. That's his opinion FWIW. I think it is possible the FSA may be a little stiffer, since the DA is so hollowed out to make it lighter, they may have sacrificed a little strength for weight in that case. In reality, I think the new Ultegra crank is probably stiffer, since it isn't hollowed out quite as much, and has a little more metal in it. But, it is heavier.