Would you rather find out aliens exist or Atlanteans

Alien Scenario: A hundred alien spaceships come down to Earth and the aliens say that they come in peace and simply want to integrate with humanity. They provide various new technologies that cure diseases like cancer and help massively reduce world hunger, but you notice that they are very interested in the metals on the planet as they set up mining operations across the globe. The aliens are about half the size of the average human and not that strong, but they do carry around small ray guns and there ships have laser cannons on them that the say are simply for defense purposes in space.

Atlantean: The lost city of Atlantis rises from the sea and the people of Atlantis reveal themselves to the world. They are all around seven feet tall, with gills on their chest as well as the are 2x stronger than the average human. They demand that humanity leaves the ocean alone, stop all forms of fishing and deep sea mining. The Atlanteans show that they also have really advanced technology such as advanced bubble shields and hover vehicles. They also command all sea creatures.

Which world would you rather live in and why?