You could probably get close enough with a Tyros 4/S-950, KORG, Audya, Etc units.. to many of the sounds heard in this video...just sayin' whats all the fuss?
As Bachus says above, there is a lot of real time control on the panel, which, coming from an analog synth background, I really like having.
Also, as Bachus said above,
not everyone is going to use these instruments out gigging, but, if needed, this piano wouldn't be all that hard to gig with, plus the Tyros4 would sit on top, negating the need for a double stand.
When gigging, I always allow lots of time for setting up, and I never book more than one gig per day...I just make sure I charge enough so that one gig suffices.

This piano would be a terrific controller for the Tyros4 as well as being a separate lower manual, with obvious room beneath for bass pedals if necessary. I'm primarily interested in this keyboard as one which will be set up in my apartment (we already have a digital piano in the studio) for working on piano based pieces.
Plus, I think it looks really cool! Very much like the love child of an affair between a Fender Rhodes and a Wurlitzer EP-200.

Ian