I think it's a mistake to have the backdrop raise to reveal the orchestra during the last number, as the audience erupted in (justifiable) applause that drowned out the ensemble for the last minute of the song. Basically the audience treated it as the curtain call even though the final number wasn't over yet. Definitely detracted from the emotional impact of the finale.
And I wasn't crazy about how the show treated Allie's eventual recovery of her memories, which happened not while Noah (or even the physical therapist) was reading to her, but when she was alone on stage and at the very beginning of a scene with no real lead-up. So when Noah then entered, she already knew who he was. It would be far more powerful if we could see the moment when she recognizes him while he is reading to her, and see him react to that recognition. I felt a bit cheated of what could have been the most emotional moment in the show.