apparently, according to a psychology phd student i know who was certified this year (and whose research i assisted by undergoing a rorschach inventory, among other things), they have been shown to be just as effective at displaying signs of mental illness as empirical psychometric measures.
i thought for sure it had been debunked, but apparently it's as alive as ever. who knew.
(it should also be noted that the modern test uses a different, less projective system of measurement called the exner comprehensive system, which is considered to be a large improvement over the prior system, that had several issues with tester projection.)