BACKGROUND: I've been using this for exposure testing with Hasselblad and Mamiya (medium format) cameras. Yes, some people still use these things without digital backs, especially for educational purposes. For those who aren't familiar with pre-digital medium format photography, these cameras have backs that contain the film which can be removed from the camera without exposing the film. Unlike a 35mm, you can put some instant film into a "polaroid back", load a roll of 120 negative film into a 120 film back, put the polaroid back on the camera to get some instant feedback as to whether your setup is working, take two shots, then switch the back to the 120 for taking the real photos. This was particularly important when you had multiple thousands of dollars invested in a studio setup for a several hour shoot and you needed some assurance that your camera and settings were working properly. You could then switch the backs again when something changed without wasting all of your unused film. This also allowed people to change the ISO on cameras without wasting film before digital sensors. At this point you hopefully have new appreciation for how the average consumer with a $100 camera can now switch ISO settings at will and view their photos immediately.
ACTUAL REVIEW: The FP-3000B works well for what I'm using it for. Using a Sekonic exposure chart, I took a +/- 1 stop 3 shot bracket of the chart with this film to help me calibrate my light meter for the film/camera and test the exposure latitude of the film. The chart basically has gray patches with 50% reflectance in the middle with patches going down and up +/- 2 stops in reflectance in 1/6th stop increments. When properly exposed, the FP-3000B shows detail in the whole 4 stop range of the chart. Given that the lightest patch shows up as barely darker than the white of the paper, and the darkest patch is very slightly lighter than total black, it's clear that the film has a 4 stop (4EV) exposure latitude which is pretty good.
So, if you're using a light meter, just make sure that the darkest significant areas are no more than -2EV from correct exposure and the lightest areas are no more than 2EV from correct and you should get detail everywhere. (If you don't have a dedicated light meter, take a (D)SLR and use the spot meter in that to meter a scene to give you a general idea of what parts of the scene are light or dark enough to render detail.
So, good stuff for fancy expensive medium-formay pro cameras, and no doubt just as good for "vintage" consumer cameras as well. Just don't get the nasty chemicals from the peel-off on your skin or clothing. That stuff is caustic and bleaches fabric.
Glad that Fuji is still making this stuff, even if they've killed off pretty much all other versions of the instant B&W film.