I have used a
Sinclair before and it did wonders.
I have also used the Innovatech one before, as well as National's.
After thinking about it, you might be better to cut and remove the sub floor with it. I would think a flooring machine might tear up a wood floor pretty good. I removed a parquet floor in Bellevue Square that was bonded so it hard, that is was removing the topping slab along with it.