anybody own both?
im currently running ultegra 6700 di2 on two bikes but have been offered a complete dura ace 7970 groupset for a very good price
now from what ive read the two systems are not interchangeable (unlike dura ace 9070 and ultegra 6700)
the wiring is different and the ultegra 6700's firmware and diagnostic device wont work with 7970 (but will with 9070)
is there any other issues?
would i be better off staying with my current ultegra 6700 di2?