Like MBP, I usually drop the reins to the buckle at the end of the ride and just steer with the the legs at the end of the ride. Vinnie will move from my leg quite well, but not in a complete circle (I was testing it out yesterday as a matter of fact). I've never trotted/cantered him without contact, but I think he would respond, if anything, to my voice.
As a matter of fact, he does better with voice commands in downward transitions than seat/rein commands. Whether that is a good or bad thing, I haven't decided ;)