Due to the impact of the recent pandemic, the teaching and learning experience worldwide was marked by a wave of emergency digitalization. The sudden need to transition to online teaching and learning (OTL) has forced Higher Education actors to adapt quickly without proper planning. This study examines teachers' perceptions of the benefits and challenges posed by OTL during the pandemic in Higher Education. Data were collected from 636 teachers from 54 different countries using an internationally distributed online survey, and responses were coded using thematic analysis. While the main benefits perceived by teachers relate to flexibility (in tasks execution), accessibility, pedagogical innovation, and self-regulation, key challenges emerge in domains such as engagement, interaction, infrastructure/technical support, assessment and pedagogical practice. Our results further suggest a phenomenon that we describe as a "double-edged sword" with elements of OTL being perceived both as a benefit and a challenge. Results and implications for OTL and future blended practices in Higher Education are discussed.