Well, if we want to look at the axiom "train the way you fly, fly the way you train", what do you think of this item doing the rounds on LinkedIn at the moment?
If you're an Airline Cadet, the latest glass cockpit trainers are ideal, but If you're going to be starting out in a typical Aussie GA relic, are you truly 'job ready'?
As for GPS reliability, its great until its not. Hasn't been available close to Syria for a few years now.