I suppose I will get the usual blowback from some, but here goes.
I have been flying MFS products since their inception, Yes I am that old.
Presently and exclusively I fly FSX Steam, the A2A, B-377, with Rex Real Environment Extream Plus HD, FSUIPC registered, all Orbx scenery packages and ForeFlight professional.
I built my own computer using the most powerful components on the market as of 2018.
My ultimate goal was to fly trouble free 6 hour plus flights with ( No Omm’s) and extremely smooth 50 plus fps, and with no less than 35 fps @ airports like CYYZ which will really grind down your FPS.
I have achieved my goal using FSX Steam.
As for being a 32-bit system I personally have nothing but good things to say about FSX Steam.
I did have problems if I got to greedy using HD clouds in REX, ( Definitely not needed, 1080 is just fine ) while Orbx Vector was the worst addon I ever bought.
I turned off Orbx Vector and all my OOM problems disappeared and I honestly can’t tell the difference with it being turned off.
My suggestions if like me you want to stay with what I believe is a very stable platform ( FSX Steam)
1) Buy/Upgrade to the most powerful equipment you can afford especially look at the 980/1080 GTX ti Nvidia graphics cards.
2) Don’t use or buy Orbx Vector, the rest of their product offering however is simply superb.
3) Try to keep your addons to a minimum, keep only those add-ons that you really feel enhance your experience while being trouble-free.
4) Read Nicks guide, his last and most definitive guide, read it over and over, study it like a College Course.
It's probably the very best advice ever written for this hobby.
As for Prepar 3d, I have seen it, I have flown it, but I seriously can't see what the big deal is.
For those that have stepped up to this massive reinvestment and are pleased then I am happy for you, and for the future of this hobby.
We can't afford to lose anyone, we want this hobby to grow with the technology advances.
As for me I have never ever enjoyed this wonderful hobby more than I do now, being retired I fly by the book every day trouble free.