I don’t think the new version 5 of SAS is as good as the older v4 was. I stopped using it out of frustration that the right click scan option is only present if SAS is running or is in the system tray (which means it’s running in the background). MBAM’s right click scan is always available. There was a recent test done of antimalware products where SAS failed miserably and both Avast and MBAM passed with flying colors. MSE also failed completely.

http://malwareresearchgroup.com/2011/06/mrg-flash-test-29062011/