The only real problem I've noted with my HF quick hitch is that the top hook (which can be adjusted in height) does not extend very far from the QH frame, leading to potential interferences with implements where the top pin (for the QH) is recessed into the implement frame.
I know this is a little hard to explain and I don't have any pictures, but when I use it on my Frontier BB, the bolts that hold the QH hook onto the QH frame hit the vertical members on the box blade top link framework before the hook can get to the pin. Therefore, I have to use the accessory top link.
I have two explanations for this, both of which I think have some validity. The Chinese designers of the HF QH didn't realize that if they made the top hook an inch longer (front to rear) it would attach to almost anything. (I may add an extension to it myself.) Also, I think the Frontier BB is designed specifically to mate up with the iHitch and not to just any generic QH that meets the standards.