I live in Grove City and monitor them daily. The Columbus Site is the best site, and it has the greatest range. I have never 'not heard' their traffic on the Columbus Site. (and this is in a 2+ mile radius).
I have listened to them on the Discovery Site but it's range is limited, even in Grove City (I'm just a couple miles away). There have been times while in Grove City where I heard them on the Columbus Site on my G4 just fine as always, yet simultaneously on my scanner which was locked on the Discovery Site they were garbled or non-existent. I have never heard them on a county site.