I would also like to touch on yaw control in this thread, since i see this as the biggest single weakness in intermeshing rotorcraft. Most do it by differential yaw control, either by torque biasing or differential cyclic.
The Unicopter concept has twin rear pusher props, which will allow a very natural and responsive pilot yaw control in all flight conditions. My thoughts on this post are really for the Synchrolite concept, which has just the twin main rotors, since this may suffer reduced yaw response in conditions of slow speed reduced loading (not sure if there was a controlled rudder) - a climbing pushover for instance. Remember that i see the main advantage of the intermesher as being performance (especially if gyro stability augmented).
Apologies Dave, it must really seem that i am joining the "throwing sharp pointy things" brigade!
I am honestly just trying to get to the bottom of what i believe to be a good concept, that just needs a little grounding in engineering common sense. I am just this bad as a professional truck designer - but the product really does benefit.
Mart