Often a user will be added in Salesforce with the same email address as another user (often because its a required field and the person entering doesn't know the real email). Since Savio only imports one person per email address, I am not missing many users, especially since I have no control over which person Savio decides the email really belongs to. As a result, one of our co-founders can't be selected as a feedback person, because he once put his email in for a potential partner, and so that person "has" our co-founders email. (ex. Mike Tomby "is" firstname.lastname@example.org in Savio. Scott doesn't show as an option despite very much being in Salesforce).
I know the right answer is just only use one email per person in Salesforce, but I don't have the authority (or the inclination) to go in and change tens or hundreds of contacts emails (when I don't know the correct emai, which is why duplicate emails were used in the first place.