Everybody's idea of everything is different. You can see all four shows and most of the major attractions in a day, maybe!! For us, we can spend 30 minutes at penguins with Quick Queue, because we love watching penguins. Wild Arctic is just meh to us, but if you love beluga whales, you could be there for a while. Also, I was mesmerized by the Aquarium at Manta, just a cool perspective looking up at rays instead of down at them. I could have spent a lot longer there. Pets Ahoy - we were the last ones out because my kids loved to pet the dogs after the show. That all adds up to hours we spend that the next family may use to "see" everything. It is a matter of style, I like an extra 5-10 minutes in the restaurants to relax. I am different than the above poster, no way would I want to see Clyde and Seamore, walk over to the other side of the park for Shamu, then walk back over for Pets Ahoy in a 2 hour span. Not better, just different. It might have been because I knew I had multiple days there, so I took it all in.
It says you are a DIS veteran, so you know theme parks. Not much different than MK in my book, we can see "everything" at MK in a day, or we could spend three days there. I know every vacation we leave Sea World having more fun than expected, hope you do as well!