As was mentioned, the key is retaining as much of the attack as possible. There have been studies that show that the human ear identifies sounds primarily by the the initial attack.  When you remove that element it's difficult to identify the type of instrument or the unique style of the player.

There is an interesting article that mentions this study at:
http://www.premierguitar.com/Magazine/Issue/2010/Mar/The_Science_of_Tone.aspx

http://thaddeushogarth.berkleemusicblogs.com/