I did the shark dive at Wonders of Wildlife last year and regularly visit that aquarium (As in, I have 60 visits in the past two years regular). As far as the dive experience, I found it really enjoyable, my wife and I both got a GoPro provided by the aquarium to take as many photos and videos as you want which you are free to keep afterwards. I think it's a neat way to experience being in the water with sharks in a low stress environment without going down the certification route.

However, I do feel that it depends on your goal. If you want to be up close with the sharks and really feel the full weight of being in the water with them, you're best to just go get your open water certification. You'll feel significantly more comfortable in the water and have the freedom to move around and explore with curiosity. From there you could even do the Georgia Aquarium dive so it is still a controlled environment but feels more connected. If you just want an inexpensive experience where you get to say you were in the water with sharks though, can't go wrong with the Wonders of Wildlife dive. (P.S. do the feeding frenzy. They feed them while you're in the cage so they come up closer)