The Ultegra R8000 series is on par with Dura-Ace R9100 when it comes to reliability and shifting performance, and offered at a lower price. 

Lighter and intuitive shifting operation
Natural front shift lever stroke
More ergonomical power curve
Precise & easy front derailleur set up
More cable routing options
Integrated cable tension adjustment
New link (Toggle) construction for no need of TL-FD90 and turning converter assembling
Adjustable cable tension on the front derailleur
Adapted for race specific frame design
Available wider front gear pitch
Shorter length of rear center with O.L.D.135mm