Recent work in immersive analytics suggests benefits for systems that support work across both 2D and 3D data visualizations, i.e., cross-virtuality analytics systems. Here, I introduce HybridAxes, an immersive visual analytics system that enables users to conduct their analysis either in 2D on desktop monitors or in 3D within an immersive AR environment -- while enabling them to seamlessly switch and transfer their visualizations between the two modes. The results of my user study show that the cross-virtuality sub-systems in HybridAxes complement each other well in helping the users in their data-understanding journey. I show that users preferred using the AR component for exploring the data, while they used the desktop component to work on more detail-intensive tasks. Despite encountering some minor challenges in switching between the two virtuality modes, users consistently rated the whole system as highly engaging, user-friendly, and helpful in streamlining their analytics processes. Finally, I present suggestions for designers of cross-virtuality visual analytics systems and identify avenues for future work.