On present generations, those worst products before were improved drastically, like QuickHeal before as their performances is really a downfall. So goes to Kingsoft and others, the thing is they have a little slight differences regarding on performance and detection issues.
But some case, an improved products went some issues that caused downfall like Avira since they still implemented the detection capabilities way that make a computer slow or unresponsive dealing in threats.
While others have a one way click perform action.