So far so good! Have you considered doing 3 different logos on spine? Like Star Wars would have the Rebel Logo, Empire Strikes Back has the Empire logo, and Return of the Jedi has the Jedi logo.
I have considered this and I think it would look great. However, because the NJVC set I just finished is all rebel logos, I kept the logos all the same for this set. I would like to create a third box set after this project that utilized different artwork and different spine logos.