In my opinion their Vietnam era New Jersey is the apex to their models. It can stand up with Neptun models.
I would put C/A and Superior in two entirely different categories. While it is true that C/A is the ancestor of many Superior models, Superior subsequently created a lot of new models never produced by C/A, and subtantially modified nearly every C/A model that it did keep.
In my youth I bought almost every 1:1200 Comet Authenticast that was made but I subsequently bought very few Superiors before giving them up to focus on the German made models by Neptun, Navis and others. So I can't give an opinion about Superiors.
But among the Comet Authenticast models available up until 1961 when the company ceased business, I would say that their Japanese ship models were generally their best. In particular their FUSO, NACHI, TONE, AMAGIRI and HATSUHARU were, among others, very good.
While not the subject here, it should be noted that Comet's wartime line of 1:500 scale Teacher scale models were excellent. In particular the all metal 1:500 models of post war ships that Comet made for the Defense Department during the 1950s and early 1960's were quite exceptional.
I think that many in our community would agree that makers such as Neptun, Spider Navy, Seavee and a handful of others represent the apex of the model-producers mountain. I also suspect that many collectors, especially in North America, got their start collecting Comet/Authenticast/Superior models. Now, I'd like people to chime in please... What Comet/Superior/Authenticast model was/is the best with regard to casting quality, fidelity of detail, and overall best "look?"