My son loved the regular round rings in the ear. The cart on deck sells them and someone brought one in. He wouldn't give it back, so I had to buy one for him. However, the ear is pretty small for the rings (plenty of room for the kids, just not so much room for the tube). Unless your baby is potty trained, they definitely won't need a float. The Mickey ear is very shallow (like an inch or two of warm water). If potty trained, I'd imagine you'd want to use the Mickey pool. This is also shallow (like 18 inches), so I float wouldn't be necessary. Also, it can get crowded so I wouldn't use the float. For the goofy pool, this is usually older kids and much too crowded for the float (at least in my opinion).
Have fun,
Jennifer