I use it for additional packages on top of another Linux distribution (Ubuntu). This gets me rolling release packages and guix shell which is great for development as each project I'm working on can be completely separated.

For 'servers' the nice part is being able to prepare a declarative operating system configuration and play with it locally (VM), then it can be deployed to the remote node and you know it's going to be the same. If something goes wrong it's easily to declaratively roll-back. Here's a nice starter post (https://stumbles.id.au/getting-started-with-guix-deploy.html). The deploy capability definitely needs more hoops to jump through and it's not without rough edges - but I think it's really cool. There's active ARM and RISC-V work - I don't know how rough that would be compared to the well-known ARM ports - ask on #guix if you're interested.