Ha1 I remember that ad! Both versions! I started to shoot a bit of Fujichrome 100 in about 87-88, and it was quite good, I remember hearing from the 'pro's' that you needed to process it at a lab that was running Fuji's E-6 process for best results, which I used in San Diego at the time. But I do recall there being quite a bit of difference with a good and bad processed batch of Fujichrome. Most of the Pro's I assisted at the time shot EPR and EPN, and 'dabbled' in Fujichrome for that 'Wild' 80's look.
During the 1991-94 redesign of Surfer magazine, it was pretty much a directive from the photo department to shoot Fuji Velvia at 100, then push one or 1 1/3 stop. They ran really washed out whites with dense blacks, and popped out colors. Just like it looked on the light table...
So, PE, do you still have a sample of the 400 speed K around? Hmmm?