The whole ICBM issue begs the question about deriving a center channel since it will not do that nor, I think, does Baam23f think it does. The ICBM is sorta off-topic in this thread.
In the (near) future, when all MCH formats can be transferred as digital signals to AVRs and pre/pros, this will become less and less of an issue. In fact, Outlaw has discontinued the ICBM in recognition of the declining need for it. That said, I do not believe there is another product that will do the same job, except the MartinSound ManagerMAX. Certainly, no digital device is available, AFAIK.
And I do agree with you about the relative transparency of the A/D/A conversions if done well. For example, SACDs fed into the 24/96 A/D inputs of my Meridian 861 still sound excellent. But, frankly, the A/D conversions of most AVRs are not to that standard, in my experience.
Kal