Compression in the same sentence as classical piano? Reverb wise they are as Raymond says similar - but if you hadn't said it was real, I would have guessed a good sample package, where the MIDI value crosses the line into the next sample with harder attack - some of the F's leap out and a player would not have played like that, apart from a mistake - the runs don't flow when suddenly a different tone note pops out. Maybe if you have used compression that is not helping. It is a very close perspective - there is reverb, but no room? I've never compressed a classical piece apart from wreck recovery when it was a bad recording. After all, natural decay is what makes a great piano put up against a poor one. What mic technique did you go for, because those changes of timbre are quite obvious?