Hi redwing19,
JDC is a good operation and the diving in Jupiter is very good. I just dived with them Feb 18 and was lucky enough to participate in the Lemon Shark aggregation. We had about 25 Lemon Sharks swimming around us on the Zion for 10-15 minutes. Reef Sharks, Goliath Grouper, turtles, are all common sights on the Jupiter dives. The 3 tanks dives on Friday and Sunday have less divers and they are generally a more experienced group.
If you don't mind another 30-45 minutes of driving, I would seriously consider diving out of Boynton Beach. The reefs are shallower at 40-60 feet and considerably more colorful. The Castor is a very good wreck dive almost guaranteeing Goliath Grouper. Underwater Explorers is a great operation and takes out only 6 divers. I've also used Starfish, they are very good too, considerably more divers.
Whoever you choose, you'll enjoy your diving in SE FL. With the exception of missing dives on the Spiegel Grove, Duane, and Bibb, I prefer it to Key Largo.
Best, Craig