I tried it for about a week in production for a handful of apps and landers then migrated off.

Pros: Easy setup on DO(1 click image)
easy to create a new app
easy deploy since you can reuse heroku buildpacks(which was great for elixir)
it just worked(unlike rancher 2)

Cons: Seemed like a lot of overhead but I didn't run it long enough to really check
Domains with ssl was pretty annoying since you had to ssh into the server and run like 4 commands for each domain
I felt like a lot of what I wanted to do required sshing into the dokku server to run commands actually