I've got Btrfs on my desktop for the OS drive cuz that was what Fedora recommended when I was installing it. It took a bit of effort to get snapshots working properly, but other than that, I've had no issues with it at all over the past year. I've got an exFAT drive and an NTFS drive in there that are kind of leftovers from using Windows. I've been thinking about reformatting the exFAT drive to ext4 or something, since all it really does is store games, and having the ability to symlink to it would be nice.
I've got a TrueNAS machine as well and that uses ZFS for pretty much everything.