>>1824824now a days mostly just weight, the groupsets have gotten so good that sora never really miss-shifts anymore. I'm sure if you really cared about how buttery smooth ur fucking shifting is dura ace would probably feel better than tiagra but its really not a huge margin.
at 105 and up you get hydro brakes which is laughable on a road bike. so better? not really. Ultegra is expensive because freds eat it up as the "well im not racing so I cant justify dura-ace...but ultegra...muh grams.."
