I can scratch that itch... I believe the rorschach to be a flawed method. As a person grows, the experiences they learn and take with them alter the natural perception of things. For instance, I may have fond memories or riding a horse and think upon a horse with wonder, whereas, you have memories of being thrown off, etc
So when the Rorschach shows an image and your answer of horse, versus my answer of horse would have two different meanings. Granted, this is an overly simplified example, but I think you can see my point and where I am going.
Thoughts, and responses do not live in a vacuum, they are not static, yet I feel the Rorschach treats it as such with a stock questions. Granted, I am not a psychologist, so maybe I am missing the finer points.
Do they do something? Yes. I believe they can, and maybe more often than we would like to know, misdiagnose people.
But that's just my opinion.. I could be wrong.