Oh, I know that there are an extremely high amount of users on DMR as I routinely update the user databases on my 878s. The amount of users is irrelevant as most aren't active even though they are in the database. Only a few talk groups get high use The bulk of DMR conversations are radio checks and kerchunking.
As for C4FM, I think that is by far the clearest and best sounding digital mode. I noticed in our area that a few of the C4FM repeaters went back to analog only. The owners finally got tired of broadcasting in an empty room.