In the past, I would rent an aerator in the spring, and do my yard and some of the neighbors. In addition to the 80 bucks to rent it, I generally ended up with an aching back, and sore muscles.
I just bought a JD420 that came with several implements--including an aerator--my wallet and my back rejoice!!
The PO made a neat modification to the aerator. It is a Brinley, and used to have two wheel-barrow type wheels that you pulled down, thus raising the spikes when moving. However, it's a pain backing it up, and pulling the lever when you cross a sidewalk, etc.
His modification was to set it up for a 3 point hitch, but also to put a swivel in it so it follows the tractor around like a trailer--saves on wear and tear on the aerator.
Here are some pictures:
It works very well. The only shortcoming is that it tends to swing to one side when it is raised, but that could be corrected by putting some stops on it--in addition to balancing out the weight on it.