I joined last year at Forsythe Farms in Markham, but they're closing down their Markham location so I'll be looking for a new CSA.
The challenge is getting a lot of one thing at once. If you are resourceful and can look for different recipes with the same vegetable, then no problem. Plus it feels good to buy locally. Overall, I found it a very positive experience and will be looking to do it again.
Note that CSA does not necessarily mean organic.