So it appears that I'm not out of the woods on this yet.
16 GB has been enough for me in most areas, but every once in a while (I noticed recently in Stormshield), I get an OS warning that I'm running out of RAM.
I guess part of the problem is running at 2560x1600. Even with 4 clients at the lowest graphics settings, they are using 1.5-1.7 GB each.

Blah!