What Mikecr said. The 6.5x47 seems optomized for the lighter bullets (123-130) while the 6CM's larger case capacity seems more readily adapted to the heavies for 6.5mm (139-142).
I'm not sure if the small primers means a lot between the two. But in the winter, you might want the extra pop that comes from a large rifle primer. It will be interesting to hear input from the 308 lapua Palma brass users about the small primers about cold weather ignition.
On the brass issue, I've not hear any major complaints about the 6.5CM brass, although the Lapua name means a bunch when it comes to the 6.5x47L.
I have 6x47L, and would consider the 6.5x47L simply because I have 600 pieces of new brass currently sitting in my locker. But if that were not the case, then like I said in my earlier post, the 6.5CM is showing itself as a very inherently accurate short action 6.5mm.