From riding them.
Yes, the technology is the same but Dura Ace is indeed their no-limit top tier group. The shifting does feel the most refined and with the best feel over the others.
It's easy to just ride it and see for yourself.
Like I said, Ultegra is 90% of DA for 50% the price.
Originally Posted by
Psychocycles
I'm not sure where the other posters are getting their information from regarding shorter throw etc, but Tim Gerrits stated directly that they are 100% identical, short of the materials (ti vs alu, etc).