I am still waiting to make a change. Why?
1. As matters stand now, MSFS is unpredictable for my money. Today you have a well running sim, tomorrow there is an update and lot of things will suddenly not work. That's pretty important if you are designing addons (chiefly aircraft). Contrary to previous sims, where you did finish a work, you now are damned to always correct your work if something is changed by MS or Asobo or anyone else...
2. Using MSFS, you are contingent on others.
Yes, the visually impact is awesome, until you lose internet connection, for example. Furthermore, in my opinion, what happens, if in any case MSFS or Asobo is knocking off the work? Will you keep everything you own?
3. What about XBox? MS seems to be keen on getting the sim as a closed system as possible and I fear 3rd-party-developpers (in most case freeware) will be barred from it.
So my two cents:
If you are happy with a running P3D(v4 or higher), wait. There is a high potential inside MSFS, but also in annoying updates that will strain your nerves permanently. In 4 - 5 years, the sim may be stable and a lot of stuff will run almost perfectly.
If you own TrueEarth stuff from ORBX, you are able to fly almost in a same virtual world, even if the internet is broken.
Each false front is only as good as the work behind. I was able to resist the truly fantastic visual reality (until now...).
Most important is, what you are keen on.
If you are satisfied with a brilliant visual game without any desire to design or change anything, you will be already satisfied with the XBox. Use the default aircraft and settings, don't expect any good AI and you will be very happy.
If you are looking for a sim you can change things at, you may be disappointed so far. The SDK is not ready at all, and parts seem not to be really accessible to everyone. As matters stand now, many (most?) freeware addons on flightsim.to are legacy stuff being converted to MSFS - which means it is far not bad. Most UK air bases done for FSX or P3D (Coningsby, Honington etc.) look simply briliant in MSFS. But they are empty without any real military AI....
I am not an enemy of MSFS, I like the truly seminal progress they did. But same with e-cars. Capability, but embryonic with a large room for improvement like infrastructure, security of electric supply etc.
Once it's given, all will be attractive to me. Not until then....