Dave,
That is quite interesting. It shows where S69 program lessons are being carried forwards. Have a lookout to see whether vertical stabilisers are forward swept for improved autorotation yaw control, and whether there is a flow seperation keel plate to avoid shuffle in hover.
It looks to me like the hover performance has been slightly compromised in order to reduce the high speed reverse air flow circle down thrust. Aerofoils suffer divergence in reverse flow, so this is quite a sensible idea. I wonder whether that interesting planform, which will be slightly more expensive to manufacture, will find it's way into conventional helicopters.
The potential advantage of coaxial is that there is no loss of downwash in the reverse flow region. I realise your arguement is that interleaving avoids downwash over the fuselage, but good aerodynamics should allow the flow to pass without too much transition to turbulance. I wonder whether that blade profile helps here too.