Mission- or safety-critical domains (e.g. crisis management, healthcare, transportation) are increasingly characterized by interactive and multimedia systems. Therefore, safe and efficient human-computer interaction and cooperation more and more becomes a crucial factor for overall performance, satisfied users and satisfying outcomes. For more than 30 years, usability has been the major criterion for evaluating interactive systems in this regard. However, latest consumer and entertainment products are often assessed and marketed emphasizing on user experience (UX) rather than usability. We will discuss three different perspectives on UX in application domains putting high requirements on humans, machines and their interaction.