Hi,
I think Paligo is a good choice for smaller documentation groups because it is reasonably priced, manages many operational tasks, and their support is good. Its layout features are quite configurable. Writers who are not yet familiar with DocBook can use the content editor. Paligo's "Source Code" editor lets you work in plain text. They have an oXygen integration for more advanced tasks:
https://paligo.net/docs/en/the-oxygen-xml-editor.html
As with any service, they have some limitations. For example, branching at the topic level can get quite labor-intensive if you have to branch an entire publication. Most documentation projects don't require that but there are days when I really miss git.
Thanks,
--Jared Crawford