The updates have become much faster and hardly slow down the PC anymore. I don't have the impression that the scans are slow. When I scan, 4 of my 12 processor cores are at 100% capacity. The other cores are hardly used.
All one really need do is configure Scans to "Paranoid" and then perform a one-time full-system scan immediately after install. After that, it is OK to change the scan type back to "Optimized" or whatever their terminology is. Real-time protection will take care of the rest. An occasional full-system scan is OK.
Emsisoft always uses a lot of CPU during system boot. No matter what system I place it on, the system fans go brrrrrrrrr... for a few minutes after system boot. That is all Emsisoft consuming 10-55% CPU. It makes system Restart take 3 to 4X longer. Then I have experienced problems where I cannot login using Windows Hello because Emsisoft is "doing its thing consuming CPU" and when that happens, you cannot login using Windows Hello. You have to reboot the system. The web portal has a lot of visual issues.
Mind you this on workstations with topped-out hardware specs. As the user I can feel, see, and hear Emsi's impact on the systems.
We will see how it goes. I will give it the Full Monty 30 days unless I have a couple more interferences with Hello login. If that happens, "Off wit Emsi's head." Sorry, but not sorry.