I programmed some remote control software using a Golang receiving program on the robot and a ruby control client using my gamepad ruby gem and an xbox1 controller. It worked OK. It was a bit jerky, there’s no PWM so no acceleration, it’s either go or stop; anything not totally rigid on the robot wobbles. Also the position of the camera doesn’t show enough of the robot so it’s hard to get a real idea of where the robot is.
I was filming, the robot was being controlled my my wife, Morwenna, from upstairs.
The robot is also prone to shed a track if the “half turn” is used too much, that is one track forwards or backwards, the other one stationary. I can fix this in software if I can work out a way to do PWM on the robot that doesn’t run the Raspberry Pi CPU.
Will writes 
Have you found a way to us pmw as of yet?
I’m now doing PWM using an atmega that I communicate to via a serial line. I send speed commands to it and it handles the motor control. Works well!