The image above is a circuit board for the 2017 NES mini controller which cost me like $10 and image below is the original controller NES-004 circuit board from the late 80's. As you can tell from both pictures, they look a bit different.
I just want to show the little differences of both controllers, so if you want to know a bit from 20016 vs this one from 1985, then please read on.
First, the original NES-004 is a bit heavier, because the cord is like 91.5 inches (7 foot or in metric, like 234 centimeters) and the NES mini controller is about 30 inches (2.5 feet or 76 cm). You can't interchange the cords with each other. The mini controller uses the wiimote port connection.
So the original controller is about 125 grams while the new one CLV-002 is about 90 grams. Of course, the weight difference is due to the cord size. Also, I noticed that the old controller's cord was thicker.
Now lets compare the insides of these controllers: On the left, its the 80's controller, while the right is the newer one made in 2016. The only difference is that the old controller has a big chip in the middle and the cable is solder to the board. The clv-002 controller you can disconnect it from the board and it looks clean.
The conductive rubber pads looks simple and there is nothing to look at.
The classic mini controller rubber pads looks similar, but as you can see the only difference is that the buttons for A and B has less rubber and the directional pad is also missing some rubber. Now lets look more closely at the NES mini classic controller. I noticed that the circuit board looks clean and it looks sharp.
Well that's it for today, the only thing I can say is that when I played both controllers (the NES-004 controller used an adapter) were used with the Nintendo Wii system, the only difference is that the clv-002 controller was too short. Other than that, both feel the same and the latency was great. I recommend this mini classic controller with an extension cord, or if you have an original NES controller, then use Hyperkin's NES Controller to NES Classic Edition Mini Adapter to be used on the NES mini classic edition or the Wii.