MSFX for a quick wazz round a procedure once you know what you are doing before you do it for the first time it is good enough. Actually learning about instrument flying it is useless and developes bad habits.
You will only develop bad habits if you let it. Fly it like you should be flying it. Get taught it first by an instructor then work through it in your spare time for free.
As for hardware: you can fly it with a mouse and autopilot - it is not about the flying dynamics but more about the procedures and situational awareness. Like I said: I found it useful for IR training for what it was. Take what you learn in the FNPT2 or real a/c and practise in MSFS. Rant does not allow you to practice the full procedures and checks with a realistic control panel which you can customise to look exactly like your training a/c (although it's been a while since I used Rant). Each software has pros and cons but to dismiss FSX as
a mass market game
sounds like you have not used it for IFR training while appreciating its limitations. That's fine - you can pick the SW to help your training as you see fit. As can I.
I'm not saying don't use Rant. Use all the tools you have to keep practised.
I suspect we will have to agree to disagree on the usefulness of of FSX.
(PS: I've not used 'X-Plane' but I suspect it would be equally as useful - or not from Mad Jock's point of view - as MS FSX)