Like others have stated, real piano is the real deal and drastically different sounding than the best sampled libraries. i have a 6'1" Kawai CA40 concert series grand, and mic'd with a pair of C12As or even km84s it sounds 10X bigger and fatter than the best libraries of 9' Bosendorfers. It's the complex interaction of the tones, especially when sustain pedal is used well, that completely blows away what any library has to offer. Hard to explain, but a real piano will express the personality and nuances of the player and his/her fingers, and then the mics capture that.
My room is not really the greatest (22 long X 16 wide X 13 high --13 ft. wood ceilings & wood floors, lots of 703 & 3 huge bass traps taking out the corners from floor to ceiling, and one corner left untreated)
I get a piano sound in this room that is really quite big and lush, so much better than any sample library I have tried that it's almost laughable.
I think it really ultimately comes down to the PLAYER. A sampled library cannot possibly capture all of the nuances of the way a great player finesses the keys, and that seems to be the major problem IMO. It's the same principle as a great drummer playing on electronic keypads that are triggering samples of real drums recorded in great rooms -- it's still going to sound fake. Actually, I think the piano is even more of a difficult instrument to sample replace than drums.
