Well, I decided to document a week living with MSE, after removing Avira from my systems. All 3 of my machines (2 Windows 7 machines, one Windows XP) used Avira, and all of them suffered the odd boot sequences caused by the software.
Avira uninstalled smoothly on all 3 machines, and, after the absurd time (15 to 20 minutes) taken to download virus definition updates, MSE was up and running on all 3 machines. I went on and did a reboot on all machines, to see how they behaved with the new software. All of them booted fully, and most importantly, smoothly, in well in about 2 minutes. Nothing blazing fast, but much better than the near 5 minutes my desktop originally took. Even my XP netbook booted smoothly, with it’s 900mhz processor chugging away. Interestingly, all 3 machines seem to run smoother, and web browsing goes quite smoothly, compared to when the systems ran Avira.
As far as ram usage goes, I never actually checked just how much was being used by Avira: however, I am certain MSE is using less, and is running much smoother than Avira did.
So, it seems this is a “so far, so good” situation. Things are going alright, but I have not put the anti virus to a true test: only my normal browsing, and web habits. It will be a matter of time before I run into my first infection attempts with the new software. That will be the real test.