It would have been nice if he did a surprise one off performances of songs like Liberian Girl, Who Is it, Lady In My Life. It's not like these songs needed choreography that he needed to rehearse and perfect before he could perform them live.
But the biggest issue wasn't even that he performed pretty much the same songs during each tour, but rather he performed them the same exact way on each tour. For example, Beat It was always performed with the cherry picker. Wanna Be Starting Something always had a pause during the middle of the song. She's Out Of My Life always had a fan come up on stage. There was no difference in watching them songs from one tour to the next and that is what frustrates me the most.