I prefer to use EGT for my tool to determine detonation. Here is a good
link to how EGT can be used and what signature detonation produces with EGT. I used EGT a lot on my 2 stroke Kart but the concept doesn't change for 4 stroke engines.
Knock sensors aren't reliable with perhaps the exception of those used in the Nissan GT-R (at lot of R&D was put into them) -- don't see them used in racing much at all, it's primarily for street use to help with "Bad gas" when one thinks they're pumping in 91 octane (and paying for it) but due to a mess up at the station they're getting a 87 or some less mix (this does happen more frequently than it should and the fines if "caught" are relatively low -- not suggesting stations do this on purpose but...).
But from manufacturers stand point, a false positive is fine by them cause it errors on the side of caution (and hence saves warranty claims). It might be good to monitor the knock sensor, but it might not be so good to actually allow the ECU to pull timing based on it.