Dob-----Are you by any chance an attorney? I noticed you didn't answer the question I posed: Have you actually done a comparison listening to the amps running in both modes? It would be interesting to hear from someone who has done this.
With the Sunfires, to run in mono-strapped mode, you need a single-ended cable input. My cables are balanced, so I can't do this, and I just run one channel through each amp. Hence, my interest in hearing from anyone who has actually done a comparison like this.