The Yamaha AN1x Synthesizer mailing list

Good sir, 
If you want a good piano sound from a yamaha
( korg M1 piano, Alesis Grand )go with a CS6x. As others have said here,
the AN200 is a VA synth recreating the sounds of the anolog beasts of
yore ( I have an AN1x and a CS6x.)
The CS6x has some great pianos, and you can pick one up off ebay
cheap, well worth the investment! Good luck :)