RT has no real workflow, more a set of tools that you might apply somehow, GUI reflects that, seems unorganized. DT seems to have more advanced algorithms and tools.
Both are excellent. Does not hurt to have both in your toolbelt.
I should probably participate in DT's tracker and try to get the few shortcomings fixed... that should do for a new year's resolution: more participation in OS communities. :)
DT also used to not do a good job on lens corrections (I have an X100T). Perhaps this new version does better since there was a mention in the changelog about lens data.
The best pictures are still the SOOC JPEGs -- too bad if I want to adjust the shadows or highlights.
I generally just stick to a couple of jpeg presets.