I know this is a REALLY old thread, but I'm actually the guy who started this thread. Obviously I thought I was convinced of something that simply wasn't true. The piano's really don't sound that much different. But I think what made the difference to my ears was the EQ's on the mixer and the acoustics of the building. I now have a pretty sophisticated setup at home and my RD-300 is hooked up to a reverb unit. I have my EQ's setup on my mixer and so the end result makes a very good piano sound. Still doesn't sound like an acoustic piano, but that's not the sound I am going for. I like that whole 80's electronic piano sound.
But like I say, I was wrong about the sound being "so different". I now play full time at my home church and we have a Roland FP-9 (we replaced the RD-300 with that keyboard), but the sounds are too acoustic for my taste. So I went and bought a Roland MKS-20 rackmount module which has all the sounds of the RD-300.
I kinda laugh at my posts now because I sounded so uninformed about everything. But I guess when you're 14, you're not expected to know everything.

[This message has been edited by RyanS (edited 01-27-2006).]