We've done two. The first year was a co-
op and all of the food we received was from the one farm. It was mostly greens, a lot of them strange and unidentifiable to me. It was fun for a few weeks trying to figure out what everything was and then what to do with everything. But I found that I was spending a lot of time running around trying to get things to go with the strange things we were getting. And I'm not a big leaf lover so it got old. I'm sure that varies by farm...this particular one specialized in greens. A small share cost $400 and it was 3 years ago.
The following year was a CSA program and it was through a hydroponic farm in our neighborhood in the city. We got all of the things they were growing - tomatoes, peppers, herbs, greens, fresh flowers, etc. BUT we also got many, many things from surrounding farms and local merchants - organic yogurt and butter, free range meats, fruits, breads, pierogies, pastas. This was significantly more expensive ($800 for the season) but well-worth it.
The biggest negative with the first is that it was A LOT of stuff I didn't really care for and it was a bit far from our house and driving someplace out of the way to get food I wasn't going to love got old! With the second, there really wasn't a drawback. I've considered signing up for it next year even though it is almost 30 miles from my house. I can't find anything like it around here. The portions were perfect and they had a swap box where you could leave things you wouldn't eat and take things other people left.
I don't know what the true difference is between CSA/co-
op. I always thought of them as the same thing until you posed the question. But looking back, they referred to the two programs differently.