I own a PSR540 and I have saved new styles to 3 user areas. I'm sure it could save voices and transpose configurations, but haven't done that yet. I love the Sweet flute voice. I'm thinking of upgradng to PSR550 just to get that flute. You can read the manual online if interested.
Negatives: I don't like the piano and orchestral voices. Unless you have a battery backup or keep it plugged in, you will lose your styles. Probably configs as well.