It's not that difficult to understand why 6DOF is problematic. For once a number of cockpits would need a major makeover. And - just like Caspar said - we'd need to have a similar system (i.e. lean left/right) for non-TIR users. Not everyone has the 150€ for a little bit of electronics. We simmers are often accused of elitism, I suggest we don't prove that statement any more true, okay?