Retina is the tool prefered by DISA for vuln scanning. Retina has a good number of high end features that I know about but haven't used yet. I have used it as a stand alone scanner and it does that very well. The features I haven't used are its ability to store the results into a database, compare those results, and to assign the tasks needed to mitigate those findings all through the software GUI.

Hope this was helpful.