I would strongly disagree with the experts who say spike aerating is a waste of time. I guess plug aerating is O-K if you like your yard to look like packs of hundreds of small dogs crapped in your yard. The recommendations biggest goal is to sell $1000-$1500 aerators as opposed to $200-$300 aerators I suspect.
I've spike aerated my yard most every fall the last 23-24 years and have stopped fertilizing, and the yard looks much better than when we bought this house. The prior owners used a lawn service to mow, spray fertilizer/herbicide 4 times a year, don't think they aerated. I had places I couldn't tell where I made my last pass with the mower even if I went 3-4 weeks between mowings when we first moved here. Grass grows much more evenly all over the yard since I've aerated and stopped fertilizing.
My aerator his home made, semi-mounted, has seven spiked wheels 5-1/2" apart with six spikes that pokes 3 to 3-1/2" deep holes every 5 to 5-1/2 inches. It weighs about 125# and I can add up to 400# of additional weight. It raises with a sleeve hitch, single pin attachment, I can turn with the aerator down as sharp as the tractor can turn. It backs up like a small 2-wheel cart. And my total out of pocket expense when I built it was for two semi-pnuematic tires and 28 PCs. 3/8" x 1" capscrews, nuts, & lock washers. Plus a couple pounds of welding rod. Oh, And a 3 foot 1" diameter piece of pipe. So probably $10 in 1980 Dollars.
Only change I'd like to make is build two more spiked wheels to make it wider, 44" vs 33".
I'm always amazed how many people are not interested in spending the money on a manufactured aerator, but after I post my results of my homemade spike aerator how many e-mail or PM requests I get for pictures.