You wont really beable to get all the oddball things of a mechanical device into a DSP model of the instrument, but it can do a dam good job and save your back. I will personally buy a rhodes when I can even with all its annoyances, however for now the PC2 rhodes I liked, thinking of getting there new little rack thing which should have the same sound. Haven't checked the Clava but it looks cool and never heard of the GEM.

Why people think the shrinking all this stuff into one little DSP chip makes things sound better is what is beyond me. I does make things lighter and cheaper but certainly doesn't make it sound any better.
Good for GEM if they pulled this one off but I have my doubts and will have ever less space in my house until some one proves otherwise.