Putting the motors in opposite corners seems a bit odd at first sight, but works well. I was really convinced it was a viable way of setting up the drive at last years UK Champs when I saw how well Little Hitter moved around the arena. My first try at a feather, Throk!, presently just a box on wheels, uses this set up and seems very controllable and is pretty good in a straight line. Its certainly allowed the robot to be very compact.