Great trip report!
I wish I could have stayed at the Sheraton Iguazu! After walking around the Cataratas I ate lunch in the Sheraton and snuck into their pool for a swim. It was amazing.
When I lived around the corner from La Cabrera I used to walk by those mobs that would be gathering for dinner on my way to the gym. No matter the weather there would always be a crowd and 2 hours of wait time for a table. The steaks are worth it though.