@Face and Nglazer,
Thanks for your points and thoughts. Much appreciated.
Your speculations are exactly the kinds of things, especially the variables of impedance mismatch or poor synergy that daunt me in the DAC ugrade selection process.
Wyred and others don't seem too enthusiastic about a trial period, or mention of a "loaner," and while I understand their point of view regarding this, a poor fit into a system could be expensive on a number of annoying levels. Even the idea of going to a dealer and listening to the DACs in question is problematic given these variables.
I continue to be very interested in audiogoners' careful and thoughtful recommendations; I'm definitely not interested in a bandwagon rah-rah approach.
:) listening,
Ed