Velvia (50) and Velvia 100F are two very different emulsions. While RVP50 found its niche very early on, the 100F, with an poorly enunciated palette of oddball flat greens (not even a polariser could improve these!), wierd mustard yellows and beetroot red-brown crossover did not find particular favour, and to add insult to its injury, it was one of the more difficult emulsions to successfully print to Ilfochrome Classic: the colours just did not resonate. I do have Ilfochrome Classic prints from 100F here that I occasionally dig up -- they really are horrid compared to the lush prints from RVP50. No contest!
The discontinuation of 100F was not unexpected when RVP50 remained the runaway clear favourite, along with Provia 100F with its neutral and less contrasty palette.