Dchan88 - thanks for the link. Note that the author of the original article says he does hear a positive difference in going from 96 to 192, although he offers no real detail on his sources or equipment.
On your Oppo, have you tried music that was sampled directly from the masters at both 192 and 96? Once you start doing the switching you are talking about, you are having the Oppo either upsample or downsample. My old MF A3-24 upsamples Redbook to both 96 and 192 and I do not find the 192 inferior to the 96. And 96KHz files upsample to 192 do not sound worse to me. Although, from this article I wonder if the upsampling to 192 is really getting through the D to A process.
Timlub - most people find that a well engineer 96KHz digital file does sound better than one sampled at 44KHz. This may not seem logical, but even my old ears hear the difference. But the 96KHz mastering is often done with more care than the 44KHz one, so that may be a big part of it. Lets not get into double blind studies :)
One of my concerns is just how many manufacturers are adjusting their front ends to take in 192KHz, but not updating the D to A process to pass the full bandwidth. If they are doing that because of what Benchmark and Lavry are saying, then maybe they should state that and explain why. Otherwise, they are implying that there D to A process is being done at a higher resolution than it actual is.