The sim is a good teaching aid, you can "die in the box" quite safely while practising handling emergencies that may be too dangerous to practice in the real thing. However, you are always aware that no matter how pear-shaped it goes, your life is not at risk. The big problem is getting enough realism into the simulation. I have never experienced "the leans" doing IF in the sim, but I have on plenty of occasions in real aircraft. I also worry about the loss of piloting skills expertise and airmanship that could result from this idea.