Good controller clones are hard to find - and even this one is not perfect, but pretty close!
Here are my results from playtesting:
* The DPads and buttons are a bit louder and don't feel as good as the ones in the original controller. However, they are good enough. I could play through Dr. Mario in Super Hard Mode, and that's something!
* The analog stick is AWESOME. It doesn't wiggle, has perfect deadzones and feels a lot better than the original one (in my opinion).
Overall, a pretty good replacement controller - probably the best you can find for the N64.