I was caught by the 10/27 login issue and fixed it as suggested by just doing an update at the CLI and things were good again but ever since that update -- things have been slow. The K/Start menu takes like 3 second to come up when it used to be instantaneous just as an example.
I've got an Nvidia 1080TI card and am using the "nvidia" 1:470.74-4 drivers. Not sure what the difference is between the khd-nvidia and the opencl-nvidia but am using the plain ones. I don't know if this is at all video card related but am suspecting that since I don't see any other posts on this topic.
I've also had a couple crashes of the Falkon browser which hasn't happened before. Things just seem off.