Originally Posted by
Slaninar
Differences are:
1) PRICE (the most significant one, most easily felt)
2) weight
3) function
4) durability
....
And 5) finish quality. (i.e. polished finishes versus painted) so DA is purdier than Ultegra.
Also, durability generally improves as you go up the scale, until you hit the step from DA to Ultegra. Some aspects of DA are less durable than Ultegra, i.e. the cassette with Ti cogs for part of the cassette which are lighter but wear faster than the steel cogs in Ultegra.