Originally Posted by
sam_cyclist
Carbon wheels are a bit lighter but MUCH noisier and offer a poor braking surface.
Electronic shifting from what I understand is well liked by those who use it, but a bit heavier and requires recharging a battery every few days or perhaps once a week. A minor annoyance.
Ultegra 6870 (Di2) - 2359g
Ultegra 6800 (Non-Di2) 2368g
Anecdotally, I'm averaging about 1800-2000 miles per charge, so for my volume that's about 4-5 times a year for charging. If you're recharging the Di2 battery every few days, that's some serious mileage.
Zipp 404 (Firecrest, Clincher) 1615g
Dura-Ace C24 (9000, Clincher) 1395g