I experience the original DC controller as rather sturdy, but the rubber pad below the D-pad is torn on most of the controllers I bought. Although I know new controllers are pretty cheap, it would be nice to find a replacement for these pads. Anyone know a good site with high quality replacements? ($14 at ALiexpress does not seems worth it).
I actually tried putting a pad from a PS2 Dual shock controller there, it almost fits, but is not 100% reliable.
Another option would be to repair the pads with some sort of rubber compound, but in my experience it gets rather messy, and it is difficult finding a suitable compound that fills and holds the pad together.