We went to Universal, Sea World, Aquadica, and Busch Gardens Tampa the last 2 weeks of August this year. We bought Universal Cups, with refills at 79cents in the 2 Universal parks, and then bought Sea World cups at 99 cents refills in Sea World. Then, when we get get to Busch Gardens, we were going to get that park's cup, when we heard and read, that at all Busch parks, and including Universals 2 parks, will refill any 32 ounce or less refillable cup at the refill rate. So, to test, we use the Universal Cups at Busch Gardens with no issue (99 cent refills). Thinking about it, I remember seeing Sea World and other non-Universal cups being charged the refill rate at both IOA and Unversal with no issues. We also used the Univeral cups at Aquadica with no compaints, 99 cent refills.
Kids got me for 4 cups that we really didn't need. However, I must say, the Sea World cups are nicer, as the Universal ones we got only have paper glued on to say Universal, and Sea World's cup has designs on the cup, not glued. I am sure with enough washing, we will only rermember that cup came from Universal. And for that, I think of the cups as the kids' gifts that are good gifts because they are reusable and will be reused again and again.