I have used Norton for many years. My former employer (from whom I retired in 2006) offered it to all employees free. It was the 'gold version' and never expired ... well at least not until I retired.
The company that provides me with my internet connection gives all users Norton AV for free. My current version is 19.9.1.14 which is not the latest version, but still quite effective and automatically updates itself, constantly runs in the background, and does a complete scan one day a week (per my settings).
I have not noticed any degradation of PC speed using Norton. I do have 16 Gb of Ram, however, so I can do lots of multi-tasking on my PC and not worry much about loss of computing speed.
I've always had problems with McAfee on any system I've owned. I have to carefully watch what I download from other sites as those downloads often include McAfee by default and I have to uncheck the box to make sure my system doesn't get contaminated with McAfee.
I guess it all boils down to what works for each of us. I've always been please with every produce Peter Norton produced.