To the best of my knowledge this controller samples at 30Hz, so running an emulator at 59.94Hz NTSC only gets you 1 input every two frames. For the casual player this would easily go unnoticed but this severely affects my ability to play with the precision required for classic tetris on level 19 and beyond. And the icing on the cake is that the down button on the d-pad is less sensitive than the rest of the d-pad which requires the button to be pressed all the way down to register an input.