I have friends in Opus Dei and Regnum Christi ... neither of those organisations appeals to me, but their membership doesn't come off as brainwashed freaks. To me, anyway.
Haven't heard much of anything about TFP, care to fill me in?
I have heard some disturbing things about Regnum Christi, but only in regards to their boarding schools, from former students. (nothing of a sex abuse nature or anything but deliberate undermining of parents in a cultlike manner)
Then again, I have yet to see a truly successful Catholic boarding school. The few I have any experience with are truly awful, but I have had limited experience.