Can'T say, I do not use FSX. FS9 has a default version of FSUIPC, whcih I also do not tweak in any way. I aolso do not know the Airbus sim, as I told you when giving you the link.
What stick do you use, and has it a throttle wheel like the Fighterstick does? The throttle axis on the ProThrottle should not behave any different than the wheel then, assuming you bind both in the same way into the sim. thzat should help oyu to assess mif it really is worth it for you to spend the money. If you do no other sim flying than just this a320 for preparation of your real life intentions, then I would say it is not. But if you do fly a lot via simulator anyway, a throttle is worth it indeed. Plus pedals and trackIR.
How is the sim? You promised us a review...!