Honestly, 100-150mi I was good - it didn't make a difference in that 50mi race, I did a couple of kamikazes that didn't pay off,lol

I was coming from SRAM and had to get used to 2 "levers" or buttons again. I had Tiagra before and didn't like the throw for the lower gears.

another thing I like about the Di2 is the shape of the hoods. As a person who have small hands it's god-sent.