Executive summary: Almost all traffic for HCSO and HPD is on conventional. There hasn't been much traffic lately. I don't recall ever hearing GPD on either MARCS or conventional.
I listen to HCSO and HPD daily on good ol' VHF. There isn't really any GPD activity that I have heard. Listening on the Scanner Radio app (I belive the local Broadcastify feed is decoding digital as well), I have rarely, if ever heard anything on MARCS. The few times I've heard the ONE officer and dispatch refer to using MARCS, the officer usually has radio trouble and they resort to cellphone.
If you are local or in the area sometime, drop me a line on here. If you are an Amateur Radio operator, we can chat on the HARA 2m repeater. If you are a GMRS operator, we can chat on Dayton/Middletown 700 (I will ask the owner for permission by telling him your callsign). No reliable simplex for me yet as we sort out masts and towers.