For me it was learning the cockpit controls, although they're not too hard to learn they are pretty detailed so I still don't fully have them learned. Using the controls with VR is reasonably easy as the game was built from the ground up to be used exclusively in VR (Although there are mods that can make the game playable on flatscreen).

That being said it's not perfect, but it's pretty damn close, and for the most part I've found the joystick and throttle controls more accurate and usable that I have with physical controlls, but that being said I've never tried an expensive HOTAS set up, which might be better, but then I'd also need to get a surface I could put a HOTAS set up that was usable. With VTOL VR I can just sit in a chair in the middle of my lifing room and all the controls are where they need to be at the tip of my virtual fingertips =)

Which is more difficult to learn in VTOL VR, learning the cockpit controls or using those controls with VR handgestures?