GRE@T-PIONEeR is a Horizon 2020 project coordinated by Chalmers University of Technology, running over the period 2020–2024. 18 university teachers from 8 different universities located in 6 different countries gathered forces to develop and offer advanced courses in computational and experimental nuclear reactor physics and safety. All courses are flipped hybrid courses, i.e., students work on online preparatory activities at their own pace before attending a set of interactive sessions organized on five consecutive days. Those sessions can be attended either onsite or remotely. During the academic year 2022/2023, 8 different courses were offered, and 185 students successfully completed the courses, with a success rate of 87.7% for the students taking at least one activity during the interactive sessions. Student behaviour and performance were monitored via the Learning Management System (LMS) used in all courses. This paper presents an analysis of various metrics from the LMS and demonstrates a high level of engagement of the students committed to the courses and a high success rate for those students. Whereas all students are equally engaged in the online preparatory work and perform equally well, significant differences exist during the interactive sessions between the students who opted for onsite participation and those who attended the sessions online, with the onsite students outperforming the online students.