The video looks great, but I just rented one of these and while trying to till our garden, it either stands in place digging a hole, or runs across the grass doing absolutely nothing.
If you are tilling firm ground you will need to go over it 3 or 4 times in different directions gradually going deeper by holding it back a little to start with. Trying to tiller to 8 or 12 inches in one go will not work.
