Windows Defender or Eset? Which is Better AND can they work together?

I have used Eset for the last 4 years or so. It always seems to be a good
antivirus software - but what do I really know?

Recently a friend told me to save my money and just use Windows Defender
for Windows 8... he said Defender is not only "free" - it is w-a-y better than
Eset. That is hard for me to believe, but maybe he's correct?

I'd like to hear from people out there who understand this situation.
Should I chuck my Eset for Defender, use both (can they actually
work together at the same time?), or stick with Eset?

 

Stick with ESET. Defender/MSE is a basic product - not even the best free AV let alone the best overall.

Here's a bit where Microsoft admits it - Microsoft Admits That Third-Party Antivirus Is More Effective Than MSE

And here are the tests:

AV-Comparatives - AV-Comparatives - Independent Tests of Anti-Virus Software - Real World Protection Test Overview Check out the baseline- this is MSE/Defender. You'll notice it's usually the worst one or somewhere in the worst three.

AV Test - AV-TEST - The Independent IT-Security Institute: Jul/Aug 2013 (Notice MSE being the last on the comparison)