Maybe we should be asking how much time we spend on it. Me?, well way too much according to my wife. But she sez it's better than me out chasing women. I've been enjoying orbiter now for 34 months at an average of 2 hours a day = >2000 hours.
One for general use with Dan's DGIV, another is only for David's shuttle fleet, another is for NASSP Apollo, and the last is for testing addons with all the main addons I already like to use.