The only Polaroid film that was sharp for medium format was type 55, and you needed to check the negative with a loupe. Polaroid was mostly good for checking lighting and getting client sign-off before committing to film.
Both Polaroid and Instax films, indeed, all instant films, including the 35mm instant Polaroid roll film, take experience and forethought to be able to use effectively, more art than science, and many will fail to develop a feel (no pun) for it.