The major objection to PC sims for those who are going to fly for real is that they teach you to fly "head in the cockpit". Lookout goes for the chop. That is, in my view, the major danger with using one.
True; a lot of that though is down to how clunky the viewpoint interface usually is. A
TrackIR changes this completely, I'd certainly recommend one for anyone planning on spending a lot of time in any modern sim (it's widely supported) - the immersion factor goes through the roof.