Welcome to the club! Unfortunately I can't answer your question as I don't use Joplin Cloud (I use Onedrive for sync) but wanted to welcome you as a fellow former Evernote user.
Importing notes was less painful than I thought it would be and I like how Joplin just does what it is supposed to do. It isn't fancy but it doesn't need to be.
There is minimal documentation on the website around Joplin server. You really have to dig to identify that it exists as a solution. I took a few minutes and don’t immediately see the installation guide on the website. It’s tough to drive adoption when there isn’t much visibility into the solution.
The Docker image has been downloaded over 5 million times so probably more than a few people are using it. Keeping it up to date usually is trivial - you just bump the version number then docker stop / docker start
I'm running the server since ages and didn't saw big issues so far. Updates a usually easy but once I took me an hour to understand, find and fix Experience and upgrade hints for Server upgrade to 2.14.2-beta I have it integrated with my traefik reverse proxy so it's exposed publicly with proper TLS cert. Setup is easy if you are not bloody beginner with docker.
The only big shortcoming remains SSO integration. LDAP was added shortly but - I hope more modern OpenIdConnect will follow soon.