I guess most of us simmers have faced your dilemma and the choices very much depend on budget and personal preferences. You should be able, with some experimentation, to get TrackIR working well. Be sure the camera is not receiving extraneous IR signals, from a window for example. A good VR headset, like Reverb G2, along with a high-spec PC provides a great leap in immersion, albeit with somewhat compromised visual quality and frame-rates. You might consider postponing a decision for a few months until the new VR headsets get reviewed.