Originally Posted by miamijim
While I dont know the specific differences between the two, you can be sure its more than weight and price. In general, Dura-Ace components have higher grades of materials used in the pivot points. This gives the components more longevity and better long term performance due to less 'slop' in the pivots over time. There tends to be more forgings and less castings of a components individual parts as you move up in any companies line.
If the only difference is weight, where does the reduction come from? Its not from shaving and drilling!!!!
As an example, I have a Dura-Ace headset with a titanium oxide coated fork race....Hmmm....dont ever recall Ultegra having one of those....
Dura Ace is lighter that dosen't mean it will last longer. How long do you need a rear derailleur to last? You can buy 2 Ultegra derailleurs for the price of one Dura Ace. I wonder which would last longer?
I don't have anything against Dura Ace but all the good riders I know don't use it(riders that buy their stuff). I also know a couple that have Dura Ace and the bike never sees the road.