This Zenit 15 ia a very advanced concept. Its shutter concept is based in the EXAII camera but its body and general layout of controls are unique and very advanced It is a pity this project did'nt go ahead. Of course costly than conventional traditional Zenit horizontal Focal plane shuttered camera.
If you notice, almost none of the more costly prototypes made it to production.. in the country that produces millions of cameras a year, a cost would be a great factor.