The Disadvantages:
First of all the displayed photo along with the tour is totally a fake.
The water clarity is too bad, you will not see more than 2m ahead. The cage is not for one person, it is for group of people together we were 6.
Secondly, it is not a scuba diving, the scenario is the cage will be close to the boat and part of it above the water surface, when the shark come close to the boat, someone will shout, so you will take a deep breath and free dive under water to have a quick look on the shark if it is close enough to you remember the water clarity is too bad.
Thirdly, the boat is not that luxury, I believe it is a fishing boat.
The Advantages: You would see obviously the shark while you stand on the boat, since it comes to the surface of water around the boat.
Eventually, my advise is, if it is the first time for you to see the white shark, yes go ahead, otherwise, I do not advise you to take it.