The 2012 Shimano Dura-Ace (9070) was the first Di2 derailleur that I actually wanted - but it was hysterically expensive. The 2013 Shimano Ultegra (6870) was almost as good (and I mean 99% as good) and was half the price. I couldn't afford it - but at least its price did not induce hysteria. It was 11-speed, it was precise, it was reliable, there were a load of options for the controls if you like aero bikes etc. etc. etc.. And although it was heavy, it was not sooooooo heavy.
Just like the Shimano Dura-Ace (9070), the Shimano Ultegra (6870) was not a pretty thing. It's lumpy and all the levers underneath are just not tidy. But, unlike Shimano Dura-Ace (9070), the Shimano Ultegra (6870) was a significant aesthetic improvement on its predecessor the fat-assed Shimano Ultegra (6770).
This example is a medium cage Shimano Ultegra (6870 GS).
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