I've used their broiler booster with every batch I've done, and I've had great results. It adds lots of vitamins and is supposed to help with the potential leg problems. I've not had a single bird with any hint of a leg problem. Now, as I said, I've done it with all of my birds, and I also feed them broiler feed, so it has higher protien, so I'm not sure that the broiler booster is doing anything at all, but I like using it.
On the organic feed, I'd say no, for the same reason as Bossroo. If you're worried about the commercial feed mixes, just go to the feed store and have them MIX a batch of broiler feed. They put real ingredients in it, like corn and soy, etc. It's not "certified organic," but it should make you feel better than prebagged feed. Only thing with that though is that you'll need to get all your season's feed at once, as (at least at my feedstore,) you have to buy their mix in 500lb batches.