No, I have not tried any of them, yet; I have only grown what seeds I can get from the dollar store, Walmart, and the 99cent store in containers in the backyard. I'm a teen, and my parents don't want me doing anything that might ruin the lawn. Also, it's a suburban area, and our HOA might fuss, too. I really want to try these sources because the seeds are so cool, and there are so many choices available. Something there is bound to be useful.
These are two places that review seed companies:
Garden Watchdog
Seed Company Reviews
Risk could be decreased by trying a seed exchange like
Heirloom Seedswap,
Seed Savers Exchange,
GardenWeb's Seed Exchanges, or a permies's
Seed Swap Via Letters.