I am currently preparing to switch to DITA. The learning curve is steeper at the beginning, but I find the overall concept of topic-oriented, information-typed authoring with content reuse very attractive.
Some people might say that writing in XML is annoying, but it isn't if you have a decent XML editor. In my case, it is Emacs nXML mode. Customisation is possible with DITA-OT [1] and plugins, and yes, it is also based on XSLT. Overall, I think DITA is an industry-proven XML powerhouse. It may be boring, but it has huge potential for anyone with advanced documentation requirements.
Some people might say that writing in XML is annoying, but it isn't if you have a decent XML editor. In my case, it is Emacs nXML mode. Customisation is possible with DITA-OT [1] and plugins, and yes, it is also based on XSLT. Overall, I think DITA is an industry-proven XML powerhouse. It may be boring, but it has huge potential for anyone with advanced documentation requirements.
[0] https://dita-lang.org/dita/archspec/base/introduction-to-dit...
[1] https://www.dita-ot.org/