Squeak,
IMO the Piano is way better then the PSR540/PSR550 (better then PSR2000), better: breath sax, vibraphone, orchestral, horns, guitars,pan flute. Strings are about the same, but EM20 has no symphony strings. Yamaha has better organs especially because of the DSP's. No DSP on EM20. Sweet flute on PSR550 is totally awesome, Roland is crap,it's not a flute. PSR540 is close to PSR550, but still would like to upgrade to get the Sweet flute.