I have seen that sometimes conflicts with Kaspersky causing high CPU usage when zemana performs an update or scanning, I know how to make exclusions but for now only Hitman Pro
Emsisoft 11 with hosts rules from: https://github.com/StevenBlack/hosts
I'll update the hosts every week. This means block domain ads and trackers on the entire OS and great performance.
I configured ninite updater (free) on task sheduler and run on weekends.
I think I cover the basics on security with awesome performance mainly thanks to Emsisoft