I waited to upgrade my devices until 13.1 dropped and it's been fine so far. Nothing crashes, no weird bugs (except for that one thing where keyboard keys randomly appear in Springboard, but I've had that since 12), nothing slows down. I appreciate the small design tweaks. Overall a solid upgrade.
I have one little complaint, though: Developers should be able to set Dark Mode specific icons and Apple should make Dark Mode versions of their own icons. I think it's a glaring oversight that this is not there (yet?), especially since they've been so thoughtful about the implementation overall.