Today, immersive technologies like Virtual Reality (VR) are regarded as disruptive tools in many domains, including education. While the body of literature in the field is growing, studies that present contrasting findings are not uncommon. In fact, although there is evidence of the benefits brought by VR in the educational processes, in some cases the effects of a possible trade-off between learning effectiveness and quality of the learning experience (or QoLE) may be observed. The two dimensions are difficult to disentangle, as besides learning effectiveness, other factors like motivation, technology acceptability, workload, presence, immersion, engagement, and usability come to play. This paper digs into the above scenario by focusing on the QoLE of immersive VR-based learning and comparing it with that of two conventional approaches (a physical prop-based one and a 3D desktop application). Separation of the two dimensions is pursued by imposing equality of the learning performance achieved with the three approaches, aiming at getting rid of possible confounding factors. From the results of the user study performed in the context of a STEM-related laboratory activity, the VR-based approach appeared to be generally superior to the prop-based approach and showed several advantages over the 3D desktop application.