5D/6D/7D Forum?

I assume you want a 1D only forum since most of the posts here are about the 5D and 6D. A 1D only forum would be probably have a pretty low post volume.

The Nikon forums are split into consumer DX, pro DX, and FX. That's essentially how the Canon forums are split too and I think that makes the most sense. Mixing APS-C and full frame because of similar price points doesn't seem like a good thing.

If you look as the post volume of the three Canon SLR forums, it's about the same for each and it's less than many of the other forums (m43, etc). It's fine as it is and doesn't need redistribution, from a post volume standpoint.