Thanks Vaughan. I edited my post while you were replying because I found out I had version 54a. I also found out I'm eligible for a free upgrade to 54c. Downloading that now. I switched to Prepar3d this week, and uninstalled FSX, so I might not even use this version 54c. But hey, it's free, lol!

I see there's also that 3D upgrade from FSX but as you said that's only for P3D 1.4, so I will wait for the new installer for P3D v2.3 as well.

Where do I find this version for Prepar3d? I purchased v5.4 for FSX at Simmarket, but see no mention of a 5.4c free upgrade anywhere...

Not a free upgrade...but a reduced upgrade price. Actually, save your money...both the FSX and the native P3D are close as if touching.  Just migrate over...and you are gold....

I purchased version 54a after 2011-11-11. According to the Simmarket purchase page 54c is then a free upgrade. I purchased it and was indeed charged nothing. I assume this version will install into Prepar3d without issues using the migration tool, but still I prefer to wait for a P3D v2.3 compatible installer.

By the way, good stuff that Prepar3d!