Dragonriding (now Skyriding) aura works perfectly in the Beta.
I was able to switch from ElvUI to base UI in DF, but I /also/ had to install an addon to get into the "guts" of the base UI and unlock more hidden features to adjust a little more of the things I was looking for, as well, at least upon its' release. Nearly everything has been fixed, however, and the only thing I could really ask for is for a moveable/detachable enemy casting bar, and to be able to have mouse-over action bars that became visible / active when your mouse hovers over them.
I think many of the new changes are very good for those of us who have accessibility issues, but there are a few "tweaks" that are still needed. The largest ones for me are the data and quest data frames. I have poor eyesight and need the text to be larger. I currently use "Blizmove" to adjust those frames to be larger and more readable. I have left feedback on this subject with Blizzard but to no avail. Furthermore, I use Curse Forge to install and manage my mods. I cannot find the correct folder in Wow directories that the Beta is using for the Interface>Addons mods. I have Classic, Cata Classic, Retail, and several Ptr folders. There is a _beta_ folder, but that isn't the correct one for TWW Beta. Is there anyone who can tell me the correct directory hierarchy?
Seems the guys over at Elvui are taking their sweet time releasing a beta build for the war within. They are normally quite prompt by the middle of each expansion beta. I truly cannot stand the wow ui, and I also play an aff lock, meaning I need elvui.