I installed the sensor on the top of my inlet manifold (L-Jet Spider).
I think the mounting hole was originally for securing the fuel rail - whatever it's for, it's not in a very good spot.
I only tested it quickly, but looks very promising.
When I induced knock at about 1200rpm, I could clearly hear it over the (unmuffled) exhaust and my knock filter appeared to respond properly - but then I had what I think was a ground loop problem between the USB port of the knock filter and the USB port of my ECU, and my laptop blue-screened
I'm hoping to get back to this in the next couple of days (a friend is rather keen on installing one of my filters for some dyno runs) and I'm pretty sure I know where the problem is so will report back soon
But as far as Nords' valve gear being too noisy for a knock sensor - I reckon I could accurately detect heavy knock with a microphone from inside the car!
To mount the sensor in a better spot, before I mess about replacing studs I'm going to make up a long nut to screw onto the end of a stud, then install the sensor with a short bolt in the other end of the extended nut and see how the readings compare to it's current location.