A couple of weeks ago I picked up one of these. The best price I found was Northern Tool. It was backordered for a while, but I wasn't in a hurry. I got the 60" model, but there is a 48" model.
Can also be bought from TSC also here
After aquiring, I spent some time and extra money on pieces and parts from TSC to make it i-Match compatible. It's not quite perfect yet, but it worked for my first real use this weekend. I'm not real experienced with any other aerators, other than the cheap one that Lowes sells that basically just pokes the tip of a knife in your yard. Something like this.
With that said, I'm pretty happy with this one. I live on a hill and as you go down the hill the layers of soil change from sand, to clay, to some more decent soil types. The clay packed in some of the tines so it made it less effective, but it wasn't all of the tines. I cleaned them all out afterwards so it will be ready to go next time. Here's some pictures.