Rachmaninov plays Rachmaninov, comparison.

The big question here is whethter the Ampico roll is played back on a reproducer of the period or if the Ampico roll has been digitally remastered and perfected on new equipment. The digitized 'cleanups' of the original rolls are very convincing but in most cases the original rolls when played back on even perfectly maintained and regulated machanisms of the period are easily detected as piano rolls. It is in the manner of articulation that the problems arise .

This might have been a better comparison if you didn't tell in advance which was which. As it is people bring their preconceptions of piano roll playing "soulless"/"a mere skeleton"/etc. and shape their listening experience to fit their expectations.

The 1928 recording of Rachmaninoff playing is plainly superior to the roll. 1928 has atmosphere, intelligence, wit, feeling, a personality. The roll is a mere skeleton in stereo. (Of course a skeleton is not bad.) 1928 is the flesh and soul.

One difference between "real" and "reproduced" is in the "soft" pedal. The Ampico moves the hammers closer to the strings, like an upright, rather than shifting the hammers over so that fewer strings are hit. The quality of sound is different as well as volume.
Check out the new Bosendorfer CEUS system. A piano tech I know, one of the best in the world, said it made his hair stand on end and so he got one. Costs over $200K though. Rach is ravishing on it. Helps that it's a concert grand.

i remember that i heard from a discovery channel documentary saying that even professional pianists can't distinguish piano roll playing and real person playing, but i can't find the source of it on google, is that true? i mean, is there any experiments done on this?

...a player mechanism, and under the upper register of the piano was a DATA CD player. The CD that the Baldwin was "playing" contained all of the old Rachmaninoff Piano rolls! For me it was an almost religious experience. I know that hearing those performances on a great instrument like that, was as close as I will ever come to hearing the great man play in person. If you ever get a similar opportunity, take it! The Ampico System may have had its flaws, but on that day, for me, it was perfect.

...how perfectly whoever was playing that piano was duplicating Rachmaninoff's own performance of the piece. Half a minute later I got up and walked to the far end of the room, having realized that this was not the typical Sunday Brunch/Piano Lounge piano player—this guy was a good as I had ever heard, and I fully expected to find a well-known concert pianist sitting at the piano! To make a long story only a little longer, it was Rachmaninoff playing! The Baldwin had been fitted with...

...(some critics of his day called it his "Princeton touch"). I have never heard that sound duplicated by a piano roll. So much for the differences I can recognize.

As for the similarities? This is a true story: My wife and I were sitting at Sunday Brunch in a large and very fancy hotel in Chicago some years back. There was a group of people gathered around a Baldwin Concert grand in one of the corners and all of a sudden Rachmaninoff's "Polka de WR" started up. I was immediately struck by...

..."harder edges" that made it easier to follow voices through the various textures. Also, Rachmaninoff was a complete master at using the pedal, quarter, half and full pedaling as well as pedaling "tricks" (see the Schumann Carnival—"ASCH" section), but on the PR recordings it sounded like the pedaling was "similar but thicker" and not as immediatly coordibated with note attacks. Finally, Rachmaninoffs articulation could be extremely dry and brittle...