I shot a fair amount of HCC and H&W Control in the late 60s up to the mid 70s and found, like just about everybody else, that it could be fabulous but was so touchy it wasn't worth the trouble.
I liked Panatomic X quite a bit and generally developed it in Edwal Super 20 which worked wonderfully with it. I have a couple bulk rolls from the 80s which were kept frozen from new, but regret to say that no matter what I process it in, it is substantially grainier than my old negatives. I have not had any issues with fog or reduced speed and the tonality is very close to that of the old negatives, but the grain is much more pronounced on even semi-close examination of a16X20 print from a 35mm neg. This differs from what others are reporting but is my experience.