Yeah they run about the same speed if geared correctly look at this from our robot.
http://www.valleytech.k12.ma.us/robo...ectronics2.JPG
There left and right drive side. Drills on one Chips(CIM's) on the other. There is a slight difference when you go full throatal but all you do is keep the Chips full and let down a little on the Drills. Works easy and have been driving it for almost 3 weeks now.
Last year we did the same thing and it also worked well.