I've had DA 7700, DA 7900, SRAM Red, and now Ultegra 6770 DI2. The DI2 is worth every penny. Honestly, though, I pieced the DI2 together off of ebay. I spent $625 total and still can sell my mechanical group parts. The front derailleur shifts with so much more authority than the mechanical systems. And the auto trimming of the FD as you sweep up and down the cogs alone is worth the investment. It took me a grand total of 3 hours to install the DI2 with internal routing and get it set up.