The UI is very responsive and well done. The TF provider has been excellent and bug free, in my experience.

DO has a few features that Hetzner lacks: S3 equivalent, managed Kubernetes and managed databases. So you need to have enough tolerance for managing all of that yourself. (they do have storage volumes, so you can get there with self hosted Minio etc, but it's obviously more work)

Support is pretty good, but quite a bit more responsive if you have larger deployments.