I have been useing the B&W film for a while and found it to have very narrow exposure latitude. But never really tested. Last week had some in my RB67 and was playing around with different exposures. I quickly realized just how narrow it was. I found that with FP-100b, I only had about 1/2 stop over or under to play with. With film or digital, I can meter the skin of a subject and increase exposure by one stop (zone VI) and it would be perfect. With the Fuji instant, the skin would wash out. +1/2 stop was about right. When I tried to place a highlight into zone VII (two stops above meter reading) the entire scene was blown out. I am just learning to use the Zone system so had never used that with the instant film before. Before I used sunny 16 rule (it does work with it) and what I call "open shade 4" rule and did pretty good. That or I took a incidental reading.
With that I was amazed that I got the expsure right as often as I did when not useing a meter. I was even a little frustrated when the exposure was little off when I did use a meter. Now I know why! During the "testing" last week, I was afraid that the shutter was draging on my beloved RB67, and causeing the overexposure. After moving the film to my 195 and getting the exact same result I knew the camera was OK. So I tried my 40D and that showed the reading from the meter was also correct by the histogram. A little more checking brought me to my conclusion noted above. 1/2 a stop is about all you got with the B&W stuff, dont know about the color, but it can't be to different in that regard.
Jason