I didn't know these existed till I read this thread, so I got a set.
I knew it wouldn't be hard to make them work on the NES since both use similar circuits, and I was right.
However, the controller I received is crap. It is way too difficult to get the pair to sync up and it's guaranteed to lose sync within a few minutes of play.
Anybody have a set of these that work fine? I'm hoping I just got a bad set and this mod was not a waste of time...
Video of my trials and tribulations: