OK I found some free sample files in 24/96 at HDtracks.... http://www.hdtracks.com/index.php
That will at least give me the material to do the comparison. I am not in a hurry though. I need to find a FREE Mac OS FLAC player or FLAC converter since the hi res files are in that format.
I plan to use the Denon's internal DAC (via Toslink) to compare 24/96 to 16/44 as the same songs are avail at HD Tracks.
I am just curious about the sound difference in my system. Though in the big picture I won't try to assemble a HiRes system since, at this time, the amount of music available in hiRes is very, very limited for my musical preferences (indie and electronica to blues to 80s). I'll update here once I've done some listening.