When did you last try it? The scenery and GPS/FMC has come a long way in the last 20 years I've been an X-Plane casual, but not so sure how much of that was in the last few.
Basic things like latitude/longitude/altitude/heading should be straightforward. But then you might have problems with mismatch scenery, like missing airports/runway, different terrain heights, etc. And then the weather synchronization is another can of worms. Matching what you see with the physic model can be challenging.