"Death of Superman" stories are deep into diminishing returns, but otherwise it's a solid movie. Far from perfect, but has a lot of good things going on.
If "Reign" is not good, then my opinion of the movie will probably go down. I know, not really fair, but due to that whole "diminishing returns" comment, I feel you need a strong, strong rationale to keep revisiting the topic, especially since this very animated line already covered his death to Doomsday. Essentially, the "Reign" part is the only justification to redo the story, and if that tanks, then this whole process will feel like a waste.