Swarm isn't going away, and in fact, Docker has stated it publicly multiple times on their blog since K8s announcement, and has continued to add new features and fix bugs. Their Kubernetes integrations in Docker EE takes advantage of Swarm's built-in security for node setup. Lots of improvement in the last 6-9 months on Overlay and zero-downtime updates, but true, compared to the first year of SwarmKit, this last 6 months has slowed down in terms of PR's for new features, likely due to focus on K8s integration. Your rolling update issues were likely related to bugs that are (hopefully) now fixed.