We have now replaced the old GitLab instance totally and all went very smoothly.
We love the custom fields in issues, the feature helps us a lot when defining our issue process. I think it can also replace our JIRA instance. I do have lots of thoughts when working with OneDev and will absolutely let you know soon.
It looks very nice. The UI is very intuitive. It's very intelligent to search commits or symbols with the help of dropdown wizard everywhere, cool!
I'm very interested in the built-in CI system, especially you mentioned that no yaml files to write. Actually, it's very painful for me to write yaml files for GitLab. Just want to know is there any plan to build a cloud based service like GitHub or GitLab? We just don't want to manage the instance ourselves.