Nice review on MSE. I been viewing your AV reviews to pick out a few new and decent ones for a couple PC's.
I'm not surprised at the Microsoft Security's results. This year I put Malwarebytes along with my 1 year useage of MSE and I found A LOT of malwares detected and removed by MB-Free.
MSE did not pick up malware threats. Infected files were discovered regardless of my safe browsing habits, and using WOT addon etc.
I have since removed MSE from my PC last month.
I would rate it MSE 2/5 (Fair) not a good standalone internet protection.