After cycling for more than 40 years. I finally got around to upgrading to Di2. Where has this stuff been my whole life? The ease of set-up is amazing, shifting is crisp and accurate! The plus for me is the minimal amount of motion required to actuate the derailleur. No more wrapping your hand around the bars to change chainrings or gears. I highly recommend Di2 to anyone with Carpal tunnel. The addition of buttons... gives you more options!
GO SPEND THE MONEY... you won't regret it!