Thanks for asking. You're hearing single system. That's a Sennheiser Evolution G2 wireless with Countryman e6i headworn mic. I backed up with a 2nd wireless going into an Edirol R-09HR. The Edirol sounds better, but drifts over time creating an extra step to adjust pitch and sync. For fast turnaround, I'm happy with the Sennheiser and looking forward to the new BeachTek XLR adapter with the AGC override.
The trick is the "magic settings" on the Sennheiser system to match the 5D. -12dB for the AF OUT on the Receiver and -20dB for the Sensitivity on the Transmitter. If you listen to my other vid "Ted from RED" that was -10dB and clipped, well, Ted is also a little louder :).

Actually, there's a new trick now since I posted the above. Just Adjust the Speed of the Audio track to 99.9%. Voila perfect sync.