Silva,
the RD 700 SX is an excellent digital piano, but it's just that, meaning that all the other instruments (like guitars, organs, strings, etc) are nothing special. It can be used as a master keyboard (up to four zones with different settings) and can store registrations, but doesn't have aftertouch.
The Nord Stage Piano looks very promising on paper: Clavia has a reputation for its excellent electric pianos and Hammond sounds, and the Stage Piano will have also a good acoustic piano (the weak point of other Clavia models). Only problem is: it's not on the market yet and the estimed release date is between October and December.
Here is a link to a review of the RD 700 SX by Keyboard Magazine:
http://www.keyboardmag.com/story.asp?sectioncode=30&storycode=7865 [This message has been edited by Dreamer (edited 07-05-2005).]