Super-XX was an early (1940s) fast pan film; it was surpassed long ago by other films in speed, graininess, and sharpness. Its great advantage was that straight-line curve- and that the curves for red, green, and blue lay right on top of one another. Which made it invaluable for dye-transfer printers, who could easily make their color-separation negatives with it. So it went away when dye transfer did, for better or worse.
Of course some people liked the way it looked as a camera film- like Michael Smith and his wife and partner, Paula Chamlee. They produced beautiful work, printing by contact only.
When I worked as a lab tech in the late '70s, we used it to make b/w internegatives from color transparencies- but that doesn't men that I can comment on its characteristics now. It must be that I developed it in D-76, in a 3-1/2 gallon sink line (that's how we did sheet film there). Michael and Paula developed it in ABC Pyro, so i'm sure it will work well in any standard developer. When you make your tests, just expose generously to get past the fog.