[smitopher]

So could you tell the difference between a well mastered 16 bit/48kHz file and a well mastered 24/192 file of the same recording? double blind?

There is no definite answer to this question. A few studies have shown that trained people may have a slightly higher chance in identifying hi-res track correctly than the untrained. I know that I can't differentiate between the two, but if someone tells me that they can, I just believe them

No I don't think I could, but I tried it a few times in the past and I think the difference is that it's mastered differently.
Daft Punk -> Random Access Memories -> have te cd release and the studio master, you can hear the difference
Muse -> Drones -> also cd vs hi-res, big difference

In both cases it seems to be mastered differently.

I REALLY REALLY wanted to believe hi res was better. Now I just listen and enjoy.

Hack mastering has ruined way too much otherwise fine music.