Research experience is widely used in quality assurance exercises to benchmark postgraduate education at the institutional level. However, individual differences in students' research experience have been largely neglected. Furthermore, little is known about how differences in students' research experience are associated with skill development and overall satisfaction. This study addressed these gaps using an explanatory sequential mixed-methods design. Study 1 was a quantitative study that involved surveying 590 research postgraduate students (i.e. 421 PhD and 168 MPhil students). A person-centered approach, specifically latent profile analysis, was used to analyze the data. Our findings revealed that students could be divided into three groups based on their research experience: rewarding, ordinary, and unsatisfactory. Those with a rewarding research experience experienced greater development in their skills and higher levels of satisfaction, while those in the unsatisfactory group demonstrated the worst outcomes. Study 2 was a qualitative study that involved interviews with 10 PhD students. The qualitative findings largely triangulated the quantitative results but also uncovered emerging themes, including the importance of student-supervisor misfit, publication pressure, and the COVID-19 pandemic context. Theoretical and practical implications of these findings are discussed.