I use this with my 8 gallons shopvac in my metal working shop. It works flawlessly on hard floors like concrete. The regular floor attachment that came with the shopvac could never pick up little bits of metal on the floor, nor the welding slag remnants, nor small pieces of gravel for that matter, so I had to use both the vacuum and a broom and dustpan to clean the floors completely.
With this attachment, the rotating brush bristles pick up everything in one single pass: Marvelous!
For the price, it's a steal for hard surface floors.
(Disclaimer: I haven't tried it on carpets, so I can't comment on that type of use...)