Not Docker Swarm, but I've been running pretty much all my services on Nomad for the past 9 months or so. I very much prefer it over Kubernetes due to being less abstracted and way easier to set up, manage and operate. It's great once you have everything set up properly with Consul and Vault. We've been running Kubernetes (though only managed in prod) and Nomad (self-provisioned) extensively at work.
Properly configuring tokens and TLS is quite a bit of overhead for the initial set up, but it pays off. You 100% want to instrument your installations and configuration with something like Ansible/Chef/Salt or you're going to go insane.
It is absolutely less mature than k8s, though, and any newly released feature should be considered unstable and probably having inaccurate or misleading docs (unless it's one off those that has already been in Enterprise before being merged into the free software version).
IMO the two things that are *kind of there* but still have some missing pieces before being great are host networks configuration for jobs and integration with Consul Connect for service mesh. Hashicorp moves pretty fast though, so I'm sure it will get there soon enough.
I've been cheating a bit with mixing loads on the same physical instance while I build out my clusters at home, but I'm pretty close to a minimal close-to-best-practice setup with 3 nodes each of Consul/Nomad/Vault servers on SBCs, Nomad client nodes (the ones actually running containers) on a handful of separate nodes ranging between Rpi and Ryzen 3400G, and a glusterfs server cluster.