I recently tried to have a go with FMC flight plans in FSX. (Stock downloaded AC and Honeywell FMC). Turned out to be a big disappointment really.
And it is all ATC's fault..
I have researched and learned that ATC that ships with FSX is very limited and "unintelligent".
1. It does not "recognize" SIDS or STARS.
2. It is oblivious to the data you entered into the FMC, and ends up giving you conflicting flight levels etc.
This means you need to fly your flightplan either by ATC instructions, or by FMC, but not both.
So far all "comparisons" I have read between FSX and P3D are about graphics, the "look" etc.
But this has got me thinking now.
Has Prepar3D got a new and improved ATC, or is it still the old "less than perfect" FSX ATC?
Can you in Prepar3D, log a flight plan, get taxi clearance, get departure clearance from ATC and then once "on route,"
when ATC instructs you to "continue own navigation", are you truly done with ATC, or will it interfere with your flight levels--as happens with FSX?
Jan