The flight sim is good for learning the basic display and use of the instruments, how they react to different conditions.
its also good for learning basic instrumnet flight, turns, tracking VOR's NDB's, Holding, procedure turns and ILS approaches.
the basic flight dynamics are ok and simulate the actual flying quite accurately but without the full visual and feel then it still lacks realism, but then again its a 50 pound computer game.
Its an excellent investment in my book, its helped with my CPL and will be invaluable for my IR.
Nick