I have both in my area.
Local Universites/Community Colleges use DMR. Many towing, private ambos, disposal companies use NXDN.
If you look at your area (your county, and perhaps the counties surrounding you), and you see things that might interest you, like the ones you listed, are tagged as using DMR or NXDN, then go ahead & get the updagrades. In some areas, smaller public safety agencies are using one of those formats as it's cheaper than a P25 system.
Also remember, that in addition to the ones you see, there likely other users on DMR or NXDN. They are not in the database simply because no one, as yet, has documented the usage, and submitted it to be added to the database.