It does weigh quite a bit so far, we're working on ways to bring the weight down (Cheesing the wheels, and gears and such). I couldn't tell you how much each wheel weighs right off hand but they're not too bad.
We haven't hooked up the motors yet but just from pushing it around we find that it seems to work better than our previous tread designs. More grip, it moves more freely and turns on a dime! It's nearly impossible to push sideways (a problem we had with treads) and the gearbox should provide the speed and pushing power we're looking for.
The center wheel does have an offset and yes, it is gear driven, no chains or belts!
