I actually purchased the "Horsenality Report" for my horse because he is such a complex horse. All of the information in the report is stuff that has been published in other PP material and as a long time follower of the program it wasn't worth the $$ because it was just a repeat of things I knew. I also think it missed the mark on my horse, because it did not ask questions about situational behavior. My horse is an extreme RB mildly introverted horse who wants to be an LBE, what I mean by that is he is usually extremely skittish and prefers to freeze rather than explode(but it doesn't take much to blow him up) but when he is relaxed he is very playful, curious, mischievous, though he is usually too nervous to let that side of himself show. The "report" pegged him as a RBE on the cusp of RBI, which I think reduced my very complex horse to a rather shallow equation. Trying my best to get my money's worth out of the report I tried following the step by step "lesson plan" for my horse, after a week he was acting like a very surly LBI, I went back to our usual play and haven't looked at the report since.
I do believe in the Horsenality concept, it has really helped me with every horse I have handled, but the report thing isn't very accurate if your horse doesn't fall neatly into one category, and many horses do not. The best thing is if you can read a horse and know all of the horsenality types well enough to know where the horse is minute by minute and how to handle each horsenality type, because they can change from one horsenality to the next that fast.
I have also read Klaus Hempfling's book and had a hard time really getting a feel for any of my horses from his descriptions because he deals more in spiritual and emotional terms rather than concrete "if this is what your horse is doing he is...." terms. I highly respect and value Hempfling's work and own all of his books, but when it comes to putting a label on a horse's personality I find the Parelli diagram easier to follow.