i have the SD1. I don't know if i will rebuy a new keyboard, but, if you create a keyboard with specification of today's computers, perhaps...
A very good PROCESSOR !!!! Fast +++ not to wait 5 Min tu load a sound from the HD !!!, very good polyphonie +++, a good sampler who can read a standard multisample format, for use with comercials samples CD or software for convert to them +++

256 Mb RAM why not ??? I can add 40$ for this memory

why not programables multipads, to add some drums hits or litle midi phrases in live...

And an OPEN FORMAT for sound load !!!!!!!!!!!

Transfert files with USB format, as we can manage the HD of the keyboard from windows as a drive letter without any software

Oriental sounds and style of vega can be loaded (on option..., but can be done in the SD1 too!)