Hello Lori! Welcome to the Disney Parks Moms Panel.
During our first Walt Disney World Resort vacation together, my family of 4 (2 adults, a 4-year old and a 1-year old) stayed at
Disney's Art of Animation Resort in a The Little Mermaid Standard Suite for 5 days before switching into a The Lion King Family Suites for the remainder of our stay.
Your inquiry is difficult as there are many variables in play. We made the switch primarily for the separate room as my young son had a terrible cough and was keeping his sister up all night. By having the separate space, we made sure that everyone had a comfortable sleeping arrangement.
If you were to get 2 The Little Mermaid Standard Suites for your vacation, you would already have separate areas for peaceful and comfortable sleeping arrangements for some, but there is no guarantee that the rooms will be adjacent and you would miss out on the fabulous experience of the Family Suites.
Your inquiry puts emphasis on the comfort level of the beds and in your situation with 4 adults, at least 2 Adults would sleep on 1 of the 2 pull-down/out beds in the main living area. When we stayed in The Lion King Suites, I slept on the pull-out sofa-bed and was incredibly comfortable. However, my wife was appalled at the idea and was adamant that she would be uncomfortable. She did love how much closer we were to the
Main Building, Big Blue Pool and transportation.
For the closer proximity to all of the action at Disney's Art of Animation Resort, the exquisite theme and true Disney-Magic Experience, I would choose The Family Suites. For definite sleeping arrangements on beds-that-are-always-beds, I would choose 2 The Little Mermaid Suites.
Good Luck!
~Todd