I find real live people find instant pictures are fun for proofing but I have not shot real supermodels who might find waiting 30s annoying. Perhaps if I'm shooting a real pro model they would laugh me out of the studio for taking fuji instant proofs. I don't know.
Amusement is one thing, business another. Instant film proofing just isn't part of professional workflow in the way it once was. The price and availability of the stuff are clues, right?
Yes, they're the reason why FP-100B is discontinued.
As I just wrote above, professionally film is totally dead as far as I'm concerned.