I come from lightroom.
I have opted for darktable due to its parametric masks and being able to apply them to any layer and use fusion modes.
I like a lot its results, the filmic module, the ability to decide what to use and change order in the pipeline if it is neccesary.
But it is not an easy transition at all.
They are quite different in many aspects, despite it similar initial look.
But most of the time, when you understand how to do it at last, the results are in favor of darktable.
For the new user one of the most difficult thing is deciding what modules to use. There are too many and some of them are obsolte, you can use too many pipelines too, scene refer, display refered, lab, rgb…
Perhaps a basic mode using just the scene refered rgb an with a few modules would be desirable for thd new user.
New modules like filmic and color calibration are great, but they combine too many things in one module and too many advanced options, that confuses a new user and it is difficult to get good results if you touch what you should not.
May be it is possible to offer a simplified basic interface for them, that let you do the adjustments in a more traditional way and work well with most photos.
The contrast equalizer is amazing too.
Last versions are doing a good job in trying to simplify things and make the transition to the new linear rgb scene referred pipeline.