Mark,
I can't speak for or about any of the airplanes you mentioned except for the BobCat. My XL has 336 flights on it, and has outlived two different gyros. I have flown it numerous times when I was between gyros, and found it to be totally controllable at any speed.

All swept wing airplanes exhibit what is called "Dutch Roll'. The landing gear door/speedbrake configuration of the BobCats produces a force moment on the yaw axis when the airplane is slowed down to landing pattern speed. When the gyro gain is set properly, the rudders are active enough to really smooth it out on a windy day. The nose gear does not need the gyro, and as a result, isn't hooked to it. My nosegear steering servo is on Aux. 4,mixed to the rudder channel and therefor is "taxi-adjustable" independent of the rudders.

The gyro gain can be set up to be all but, or totally inactive when the gear is up. Simply program a mixer to set the gain to about 40% when the gear is down and no gain at all with the gear up. The final gain setting for your airplane can only be established by flight testing it.

Harley Condra
BVM REP
Team Jetcat