Right, but I'm sure you've seen gear that allows two channels to be assigned to either surround-back OR second zone duties. We don't which way the 997 will operate, since we don't have enough info on it (or its Sherwood counterpart receiver) to do anything more than take wild guesses at this time.

And quite well too. A friend of mine used to re-digitize SACD/DVD-A through his 990, and the degradation was negligible to none when compared to pure analogue bypass. Modern A/D conversion is actually much more transparent than many folks think. The Audyssey outboard SEQ box is another good example. And, as you said, it becomes even less of a concern when limited only to the surround channels.