One of the best things is now 1920x1280 is supported over DeX.
From what I just read the LTE variant isn't rolling out yet, but it is coming soon.
And now it rotates, too! (If you use DeX on the tablet itself). Finally I can use it without having to prop up the screen.
This is much needed.
After installing Pie, the quality of the better videos seems even more beautiful. Extra clarity and rich colors. I use adaptive display setting. I don't know why that would be. Has anyone else noticed this?