First, op says
Window Defender scores 100% in June Real World Protection Test
Not true, it's 98.8%. In most cases, 98.8 is close enough to be approximated as 100, but this is not that case. There are 10 AVs that score above WD.
Second, detection rate is just one side of the picture, there is another side. It's called false positives. WD has a wrongly blocked score of 27 while Kaspersky has only 1 & bitdefender scores 5. Trend Micro, which scored 100% in detection rates had the 4th highest wrongly blocked score of 53.
Conclusion: Use whatever scanner/scanners you want, but just remember this, WD is still vastly inferior to the likes of Bitdefender & Kaspersky. Basically what quietman7 said above, just wanted to clear the fact that detection rates alone don't give the complete picture, one must also look at the false positive score to get a better idea about the AV when you read reports like these.
Edited by downloaderfan, 20 July 2017 - 06:30 PM.