I’ve got only good things to say about Dura-Ace. SRAM red seems to be an excellent set up too, except for the flimsy front derailleur. I just helped a friend ‘downgrade’ to a Force FD and he says that the shifting is much better with the Force FD.
If weight matters to you (for the weight weenie inside of us!), it would appear that the SRAM RED road groupset is over 200g (>1/2 a pound) lighter than Shimano DA 7900.
http://www.totalcycling.com/...mponent-weights.html
I have both red and 7900 and while I have read similar comments about the FD many times I never have noticed a big difference. The Red FD certainly shifts perfect. The only difference is that sometimes with the 7900 you actually have to look down to see that it shifted.
While the Red RD certainly shifts louder/harder I feel much more comfortable shifting the Red one under load while climbing. It actually feels super smooth when you make a really hard shift on it.