I purchased a specialized 2005 tarmac comp about 7 months ago. I am very pleased with the bike. I want to upgrade the drive train to Dura Ace over time. The bike has Ultegra flight deck and rear Derailleur. The brakes and front derailleur are 105. I am considering swapping out the front derailleur from 105 to Dura Ace as my first step. My question is will I see a change in shifting performance with just changing out the derailleur and leaving all the other parts as is? I don't need a whole groupo at once. Thank you in advance.