I don't currently have a personal use-case for container services, but Quadlets are another example of systemd (and podman) beauty. It looks like someone has gone through the trouble of making the OS+home-manager modules: https://github.com/SEIAROTg/quadlet-nix
I never had the opportunity to try out quadlets, but they seem powerful.
I maintain one of the competitors listed in that README (compose2nix), so I am a bit biased haha.
For now, I prefer the ability to interop with Compose.