D,
I first would have to ask you what you are using these sweepers for, or should I say in what application.
Construct-wise the units are similar. The Ohio Steel may be a bit more durable in many of its components like in the gears and the bushings, but I have never heard of anyone going through 3 sweepers in 6 years.
I would first have to ask you if your brush height is set appropriately.