Hybrid Delta-Cartesian

I have been dreaming up my next printer and wondered if anyone had built a hybrid delta-cartesian printer. I am thinking of Y-Z axes provided by two delta arms on either side and an X axis provided by a more traditional cartesian sliding plate underneath the two arms. The advantage over a standard 3-axis delta would be a rectangular build volume. The hybrid delta might have a slight advantage over a full cartesian because of the lighter extruder platform of the delta. Because of the lighter weight, the two vertical delta arms could use belts rather than lead-screws for vertical motion.

(I am certainly willing to bet that it has been contemplated before, but can't find any discussions on the merits.)

Thoughts?

[attachment 35440 HybridDelta01.jpg]