Not much to say about Iguassu (or Iguaçu) other than go if you can.
There isn’t much to recommend the cities on any side of the triple border between Brazil, Arentina and Paraguay, except that they are close to one of the greatest falls in the world.
My only advice is to make sure you have at least 2 full days so as to have time to spend a day on each side of the falls–the Brazilian side offers the best overalll panoramic view, while the Argentinian side is much more intimate, with lots of little smaller falls, coves, etc, and more jungle to walk through.