X-Plane is really growing up currently. Two exciting projects seem to be near to release: a FMC for a Boeing (here) and an A320 version (here) . Let’s see which summer the latter means. September is not really what I call before summer. Anyway better aircraft system simulation is really one of the few things which X-Plane lacks to be a replacement for FS2004. If that is there I am sure a lot of people will switch to experience super smooth graphics in every moment of the flight.