Yes, some of those
are very impressive, it's hard to fault them with not knowing the music, but if I had to, then I would say that some of them are a very much, 'in-your-face'. They are like recordings made with a very close mice technique. - they lack that concert hall ambience. - That Piano is not in a hall acoustic,
you are in the piano, - under the lid!! - But yes, they are
pretty darn lifelike.
I happened to have this
Gershwin in my CD player, recorded in Symphony Hall, Boston, in 1959. - By comparison, it felt more easy to listen to, you felt 'there'. It was as if someone had opened a window and there was space around everything! .... Magic!
If I could listen to something I was more familiar with, it might be different, but just casually hearing them, I wouldn't have known they were constructed from samples.