In my honest opinion, the characteristics that will be more focused and preferred will be the Usability. To better explain it, think Usability as a nurse to a doctor which needs protection against a deadly virus and will also act as masks and gloves that are wore by conventional doctors. Similarly, as gloves, masks and nurses help doctor to function more effectively, usability will work in a similar fashion. Cost is not that much of a problem in this field, and the reliability is automatically increased as this diagnosis process is more improvable.