SRM DuraAce 9000 Power Meter (11 speed)
I traded in my Cannondale Hollogram SL power meter for the new SRM DuraAce 9000 50 X 34 unit. It will go on the bike within the next few days. The 3000 hour battery life makes it an install-and-forget thing.
The Moot Vamoots RSL is still running a 10-speed Shimano DuraAce Di2 drive train and 10-speed chain (as of Spring 2014, see notes on Lightweight wheels also). This combination is working just fine with the DuraAce 9000 crankset.