i would think with proper configuration the knock sensing built into vems would be equivalent or better than the KS-3
I was looking at the KS-3 last week before i got knock almost working
when they say 'wideband' i'm assuming they are talking about frequency response of the sensor. since you are tuning for a particular frequency and then setting amplitute (even with their unit), i'm not sure how much it matters if the sensor is linear throughout its curve, etc etc.