said by ChillBill :...with my PC still running at a snail's pace,does Avast free warn me continuously with popups about dangerous website trying to connect with my PC (22 hits every few minutes) while NIS is silent?
Uhmm... if Avast is running and warning you continuously, then NIS should not be running at all. Running two AVs simultaneously is a recipe for trouble, and generally doesn't work out well...
Beyond that, on any given day, one AV product can be better at detecting malware "X" than another AV product... no matter what "ratings" say.