Virtual reality (VR) experiences are receiving increasing attention in education and training. Some VR setups can deliver immersive VR training (e.g., on multiple projected screens), while others can deliver nonimmersive VR training (e.g., on standard desktop monitors). Recently, consumer VR headsets make it possible to deliver immersive VR training with six-degrees-of-freedom tracking of trainees' head as well as hand controllers, while most smartphones can deliver nonimmersive VR training without the need for additional hardware. Previous studies compared immersive and nonimmersive VR setups for training, highlighting effects on performance, learning, presence, and engagement, but no study focused on contrasting procedural training with (immersive) VR headsets and (nonimmersive) smartphones. This article conducts a comparison of these two VR setups in the aviation safety domain. The considered training concerned door opening procedures in different aircraft and included a virtual instructor. In addition, we compared the two VR setups with the traditional printed materials used in the considered domain, i.e., safety cards. Results show that both VR setups allowed gaining and retaining more procedural knowledge than printed materials, and led to higher confidence in performing procedures. However, only the VR headset was considered to be significantly more usable than the printed materials, and presence was higher with the VR headset than the smartphone. The VR headset turned out to be important also for engagement and satisfaction, which were higher with the VR headset than both the printed materials and the smartphone. We discuss the implications of these results.