This Willy Street Co-op is leaps and bounds over the other two. If finding a parking space at the other two is an enormous hassle, you will be able to have your pick in the HUGE parking lot that North shares with the other retailers as well as the library (yes, drop off your books and shop at Willy Street. Such convenience, there is a hardware store, dollar store and barber shop. During the summer on Saturday, you have the Farmer's Marketing taking up part of the parking lot.) Along with the large parking lot is a larger than average Co-op. I found the prices to be on stock up items to be pretty good and the the typical Co-op items comparable.
The only thing that caused me not to give a unalloyed stellar review is that their hot breakfast is definitely lacking. Yes, the oatmeal is some of the best oatmeal found in Madison. My 80 year old something Dad always gets it because it reminds him of the homemade oatmeal his mother used to make in the 1940's. But the tired breakfast bar and the quickly disappearing breakfast sandwiches are a disappointment. I realize they may not get the kind of traffic like they do on Willy or University so they plan accordingly. Maybe more people will be willing to make the trek to the north side if the hot bars were a little better, just saying.