yes you are not alone. I have found Revu 18 to be a universally worse product than the previous versions.
On my machine I found these 2d rendering settings to work best:
rendering engine: Advanced (Skia)
rendering mode: Wait for completion
_ Enhance thin lines
x Disable Line Weights
X Fill Anti-Aliasing
X Blend Modes
_ CMYK Color Calibration

It also extremely sensitive to what version of .Net you have installed on your machine we've had a lot of people with whole pdfs that just fail to render in Revu 18 until we install a specific .Net version.

Open Source Structural Applications: https://github.com/buddyd16/Structural-Engineering

Link

Don't know if this helps at all?

I found going from 2016 to 2017 quite a slowdown on the same hardware with respect to rendering. Really good way to cripple a good product by making it monumentally slow at rendering. I find things like printouts of complex spreadsheets from excel with charts and plenty of cell borders and fill excruciatingly slow for some reason. Used to pop-up within microseconds in 2016, now can take up to 20 seconds to display.

Yet to upgrade to 2018....

I find it funny they are releasing articles on how to speed up the performance of their own software.

For me I don't think it's even a rendering issue; even on 10 page text documents I get unbearable lag trying to scroll through the document.

I'm yet to find a benefit of upgrading to 2018...