Re: Not that subtle
For final playback purposes, Dan Lavry (who makes arguably the best converters going) argues that for a person with a normal ear (ignoring people who can hear 24khz sine waves) any audible improvement at higher sample rates is the DAC's manufacturer being unscrupulous and hyping above 10kHz or so, in order to make people feel they're getting extra detail. You can get the same sonic improvement at a lower sampling frequency by just applying a subtle EQ boost.
And you're not going to hear the bit depth difference (on playback) unless someone's been careless with the headroom, left out the dithering, or applied a bunch more digital processing to a 16bit source before playback, or it's being played loud enough to cause instant hearing damage. Granted it's not that unlikely that one of those scenarios is in play, but you did say "properly configured".
----This all assumes they're the same master source at different sr/bd. If they're different sources, then of course all bets are off.