I came across this rare discontinued film on ebay and I would say that's your best bet to find some for yourself. I haven't seen it anywhere since so I am very happy that I grabbed up as many rolls as my budget would allow.
Similar to its Ektachrome brethren, the 100 HC is a perfect candidate for cross processing. When shot as a standard slide for xpro you will get accented blue hues as well as vamped up yellows, but none too overpowering. Typical blocky, dark shadows and washed highlight contrasts appear and will increase with over or under-exposure respectively. I like the fact that it doesn’t make your shots totally crazy with unnecessary color. It can be used just as well for nice portraits as cool xpro shots.
I push processed a roll, over exposed some shots as well as underexposed a stop as I typically do for xpro to see the various color schemes you could achieve with this film. I came back with some interesting results and plan to have a lot more fun experimenting with this film. When over exposed or pushed it can give you very washed skies which can even appear white. This film yearns for bright sunshine with a small aperture and a larger aperture in shady conditions. At night with a flash it is a little finicky about giving a proper exposure so be weary if you don’t have a professional grade flash you can adjust. I can’t blame it too much as that is a typical fallback with expired films.
I’m looking forward to many more colorful rolls with this fine film.