For a while, I had a 7D and a 5DII (both gripped), so I had four batteries and two chargers. I would charge the pair of batteries for a given camera at the same time. When I only had one of the two bodies, I'd charge them one after the other in the one charger.
The 1-series charger holds two batteries, which is nice...but, it charges them in sequence, not simultaneously, and it's a big beast if you need to take in on a trip. The LC-E6 was more convenient from that standpoint.