Great question! Because of the peak detection method the logging frequency shouldn't too much unless you're logging at like 1Hz. I'll do some testing to try and give you a more quantifiable answer.

Ended up pulling the trigger on this a few weeks back and got around to installing it tonight. I haven't done the full calibration procedure yet, but I plugged in some headphones and fiddled with the sensitivity adjustment a bit.
Seemed to be working pretty well. Outside of getting the knock sensor installed into the block (quite tight with the oil feed, pressure sensor and coolant lines) it was a pretty simple install.

I'll probably try to test it more in the next week or two and do a write-up/review.