I have never personally flown a bus, neither the real deal nor a simulator, but everyone who did and talked with me about this very issue said it takes about three to five minutes of actual handflying to get used to it and another ten or so minutes to feel comfortable about it.
My guess would be that it is more a mental thing than anything else. If you absolutely donŽt want to get used to it, chances are you wonŽt (or at least youŽll have a hard time in the process).