I will say that I loved the musical crossover, except for two things. The fact that it was a dreamscape scenario set up by an interdimensional being was kind of disappointing because it wasn’t Winn, Cisco, Martin, Joe, or Malcolm singing. I hate that Winn and Cisco haven’t got to really meet and bond. Although, it makes since for it to be a dream with Martin and Malcolm having to deal with the Spear of Destiny over on Legends of Tomorrow.
The other thing I didn’t like was that Kara and Mon-El are back together again after a two second break up. Unlike the majority, I don’t hate Mon-El. I just don’t like and Kara as a couple. They are frankly better as friends. Kara makes him want to be a better person, even if he doesn’t reach his potential. Instead of them getting back together and the writers force-feeding a couple down the audience’s throats (like Olicity), they need to see that their relationship isn’t meant to be and Mon-El needs to go unite the leftover Daxamites and be a better ruler than his parents were.
Oh, I also have to say that the musical’s plot ended abruptly just so that the couples could reunite. Big shootout and some of the dads get hit, but nothing else from Tommy and Millie - come on!