I love the option in a studio, or long term setup. It's not important enough for me to lug to my regular shows, but if I was doing a tour - I'd have a 76 key weighted action piano-ish (Rhodes) on bottom, and a powerful synth/arranger on top. Sometimes midi connected, but even when not - the flexibility of playing two handed Rhodes as an intro, then jumping up for bass and chords while the drums play from the top kb.
Here's one vote for YES ... if you don't have to move it a lot ... or you have roadies.