Dave, reading your post #11 then the tandem is the best design for power consumption. If you have to design in an extra g/box and d/shaft it makes sense to put that that "aerodynamically remote" rotor somewhere sensible. If you put the rotors beside each other, then for sidwards flight the trailing rotor will suffer increased pitch to cope with the increased inflow caused by the leading rotor.
Unless you have extendible main shafts to find clean air?
