Last year we had single speed gearboxes geared for about 10.5 ft/s in our swerve drive and a selectable-output shifting gearbox for our dual kickers. Our real-world results confirmed our calculations that showed a single-speed gearbox geared for 10.5 ft/sec was a very good compromise between speed and traction with our customized Colson wheels.
In the future, we'll likely use 2-speed shifting gearboxes on our drive train if we go with a normal 6WD.