if he wants the training to help him out with getting a pilot's license in the future, flight sims aren't going to do that for him. they'll give him a basic understanding of flight mechanics and how an aircraft might respond, but that's something you learn really fast (or already know) anyway.
the hard part is getting comfortable in the cockpit and being able to do a lot of multitasking (being able to navigate, control the aircraft systems, keep up required radio chatter, etc)