One of the biggest problems I’ve seen is the newer versions of SU running on Windows 10 have some serious lag issues once the model gets to a certain size. I still use SU8 and Windows 7 for this reason. Newer versions of SU are trying to reference all kinds of nonsensical things just like Layout. Also, Windows 10 somehow compounds this by treating your PC like a phone. When I’m dealing with lag from a large model, I make sure to collapse my Entity Info, Layers, and Materials windows. This keeps SU from referencing quite so many things while you’re doing an operation. It also helps to turn off any unnecessary layers, or to make a layer that is just for complex geometry so that it can be turned off while working on other things.
I was researching the Windows 10 issue a while back, and at the time nobody had found a true cause or any solution. I used a Windows 10 machine at work for a few months, and I noticed that no matter how fast the hardware, this lag issue was still a big problem (less so on SU8, but still no fun). Keeping complexity out of the model helps the most. And always make sure that OpenGL settings are correct (use fast feedback and never use maximum texture size).
But no matter how bloated Trimble makes newer versions of SU or how awful Windows 10 is, I’ve never see a program as fast as Sketchup. I also use AutoCAD here and there… and a model that is 1/10th as complex as a large SU model will lag 10 times worse… and god forbid you turn faces on in AutoCAD… might as well go have a smoke if you just orbit a little.