Ok, for surround you can't beat the CBII/CBIII. However, the pre-amp is good...not great. If you want the best quality for the EMM get an Aesthetix line stage and simply use it in between the CB and the amp. Yes, it's more complex and expensive, but it solves the compromise of blending the two channel and multi-channel into one system.
I've done this before and the Aesthetix is the best I've heard yet.
Cheers,
Mike