Shim,
The PSR 1500 doesn't have megavoices but has Usb to device, Usb to host, IDC and Virtual organ drawbars. I would not upgrade a 1500 for an S700 because you only get 10 megavoices (which are great) for the styles and 29 extra voices among sweet, cool and live voices but the 1500 has 273 regular voices and the S700 only 254. Of course if I was buying a new keyboard for the first time I would choose a PSRs700 or even better an used PSR3000 with many more features than an S700 including 15 mega voices, more sweet and live voices, color display , vocal harmony and smart media card. Depending on what you want to spend, an S900 would be a much better upgrade. Read the specifications of each model before you decide. Good luck.

Victor


[This message has been edited by vagro (edited 07-19-2008).]

[This message has been edited by vagro (edited 07-20-2008).]