It was nice being guarenteed a seat at the Nemo show, but one thing I will say is that Tusker House is not that close to the Nemo show. If you eat relatively fast, then it might not be so much a problem, but we tend to eat more slowly, so it was a bit of quick walk from Tusker House to Nemo. I would recommend trying to get an ADR closer to the start of the time window.
We also noticed that as it got closer to the time of the show, parties ended up split up because the benches were getting full.
That all being said, I would take advantage of this offer again.