I feel I need to step in on the side of the Speed Limit Recognition, maybe I live in an area where the signs are clearly shown, and not obscured by bushes, or not covered in graffiti, or haven't been turned slightly in the wrong direction, etc. but mine works perfectly. I actively monitored this the other day, and every change between 20, 30, 40, and 60 was instantly recognized, and the dash display changed with almost magical accuracy.
I'm sure there will be occasions in the future when a speed sign will be missed, and I end up cursing, but right now I love it, and think it's a great feature to have on my car.