Lukitoh,
I figured the speaker set up of the PSR-1000 would be the primary reason for better sound quality.. Maybe one day Yamaha will release a new model of the 550 with tweeters that actually work and aren't just for show... That's why I don't like to use them.. I use Roland Monitor speakers for my set up.. However I figured the two boards were pretty close to the same quality.. I'd like to have both side by side running through my Rolands so that I can listen to them... Oh well looks like any keyboard is WAY in the future for me.. I'm not even thinking of mentioning another keyboard to my wife.. After buying the Lincoln I think she's pretty much shut me off for a long time...

Squeak
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GEAR: Yamaha MOXF-6, Casio MZX-500, Roland Juno-Di, M-Audio Venom, Roland RS-70, Yamaha PSR S700, M-Audio Axiom Pro-61 (Midi Controller). SOFTWARE: Mixcraft-7, PowerTracks Pro Audio 2013, Beat Thang Virtual, Dimension Le.