When I first started out I bought a used Ryan IV aerator. Worked great for me. I had some larger lawns, so I bought a used Ryan V aerator. Poor design, chain broke a few times (one chain vs. two with the smaller Ryan IV model). Then I bought a Lawn Solutions aerator. I get 50% more lawns done with the LS aerator because is goes forwards and backwards WITHOUT having to lift the tines and turn the machine around. They are a sponsor-check out the video. The people who say they like other aerators have NEVER tried the LS aerator.