Usability testing is a precursor to A/B testing where you actually seek qualitative feedback from users.

THe VWO What To Test feature provides reports like this:

Creating a usability test is a 5 step process using the What To test feature.

1. To create a new report, click on the Create New Report button in the sidebar on http://v2.visualwebsiteoptimizer.com/tools/what_to_test/credits.php.
2. Next put in the URL of the website on which you want to get the feedback on.
3. Select the number of users from whom you need the feedback. The default value of this setting is 5.
4. Select questions that you want to ask the users about the website. We provide a set of template questions that can help you getting started quickly on creating an usability test.
5. Finally, click on the Save and Run button to start the usability test.

Normally, a single test takes around 2-4 days to receive the required amount of responses  and generate a full report.

Also, remember that What To Test requires credits to run a test. These are simply calculated as the number of users asked into number of questions asked:

Credits for a test = No. of Users  x  No. of questions asked

These can be purchased by visiting http://v2.visualwebsiteoptimizer.com/tools/what_to_test/credits.php.