I downloaded the trial and played with it a bit.
There are 2
immediate benefits for me, for visualisation - linear workflow and the render queue. In fact I think there are quite a few things in there for arch viz.
I guess the acid test is whether I have upgraded yet - and the answer is no. I use v11.5 heavily and it still works great for me - but yes, I will eventually move up.
The list of new features is
here