I agree with Muggsy -- Stuart Cove's is an incredible operation. Very professional, informative, and thorough.
We did the same shark feed dive she described in April. I can't say anything more than Muggsy said, because we had the exact same experience in the exact same location. In fact, my profile pic is from the second dive on that trip (in the rock circle).
I had dreamed about diving with sharks for years, so I was all too excited to do this dive. The only time I was even slightly afraid was when I first jumped in the water, knowing there were many sharks below me. But once in, and with all the other people who jump in, AND with all the other people below you swimming in and among the sharks below, my fears dissapated. I still look at the pictures and video today, almost not believing I did it just because of how it looks, but I'd do it over and over again in a heartbeat. When you're down there, the sharks seem like dolphins and are definitely just as graceful.
Keep in mind, these are Caribbean Reef Sharks, which are worlds different than Tigers, Bulls, and Great Whites. I knew that bull sharks were much more dangerous, but I never knew why -- I heard on Discovery that their testosterone level is up to 80 times higher than that of other sharks. Great Whites will typically only "taste test" a human before deciding it doesn't like you and leave you with a pretty bad wound, sometimes fatal. But a Tiger -- and especially a Bull -- will keep right on eating.
Anyway, I just wanted to put in my two cents for Stuart Cove's operation -- a real class act. We stayed in Nassau (specifically, Paradise Island) and enjoyed the entire trip, with Stuart Cove's shark feeding dives being one of the brightest highlights.