You can skip all the junk below and jump to the Prepar3d V2.1.9936.0 announcement to get the particulars.
For those of you who haven't tried Prepar3d V2.1.9, here's what I've found so far.
To upgrade, you have to log into your account. When you're there, you'll see all/any updates for which you are eligible.
There are two ways to upgrade to V2.1.9: Do a complete download (recommended), or a patch that'll update just the portion of the files that need to be updated.
I've had more problems than I want to think about lately, so I went the full download route.
The LM development team has a recommendation;
For the best possible patching result, it is strongly recommended that you delete the generated Prepar3D files/content found at:
%PROGRAMDATA%\Lockheed Martin\Prepar3D v2
%LOCALAPPDATA%\Lockheed Martin\Prepar3D v2
%APPDATA%\Lockheed Martin\Prepar3D v2
%USERPROFILE%\Documents\Prepar3D v2 Files
I figured that they must know something, so I did it their way.
I also suspected that I would be wiping out a lot of settings, and I did.
AND THEN I HAD FUN
Not really.
But it did teach me a lesson. I now have snapshots of all my flight instrument settings for future use.
In a way, they treat the Saitek instruments no better than the way FSX does on a fresh instillation.
This is something that anyone with a Saitek throttle quadrant can appreciate.
These are the "default" Prepar3d V2.1.9 settings.
And I never knew that the Throttle Quadrant had an Axis 6 or Axis 7.
There is a lot of that type of rubbish for all of the controls. Your best bet is to go through EVERY control and delete ANY buttons.
Get rid of them first, and reprogram all the buttons from scratch. Otherwise, I can pretty much guarantee that you'll have some odd things happening.
According to Prepar3d I even have about 8 or 9 buttons ON THE RUDDER PEDDLES!
Notice that the P3d Settings/Control screen is different. THERE IS NOT A JOYSTICK COLUMN.
In Prepar3d V2.x you can have a keyboard command OR a button command. NOT BOTH!
I almost never use the keyboard commands, but I would like to have it there.
If you're using FSUIPC, you'll have to install it again. You'll see some errors like this;
I'm not sure what the errors mean, but FSUIPC worked fine.
I have FSUIPC sending multiple commands for some of my flight control buttons, and they all worked without having to rebuild the commands. Not a big deal, but nice.
With FSUIPC in it's place, SPAD worked without any problems.
PlanG works fine too.
There's an oddity with both versions of Prepar3d V2.x.
For some reason Prepar3d doesn't want to recognize half the buttons on the DesktopAviator GPS.
This irritates me because there is absolutely no problem in FSX.
And I have several ways of checking for HID (Human Interface Device) button/key press, and they all report that the GPS buttons are being sent properly.
The buttons are read by FSUIPC, and I could program that to send the correct command to Prepar3d, but I wanted to keep it simple.
I found that if you hold down the button that you want to program while you press a button near it, the correct button WILL register. Once you've done that to each button that P3D wants to ignore, everything works fine afterwards, with any plane that uses the "GPS commands (as opposed to the G1000 commands which have to be programmed separately).
Conclusion
Prepared V2.1.9 still has some problems.
But, overall, I think that it IS better now than FSX.
I'll probably end up using FSX as some use FS2004/FS9.
I'll still use FSX for a little fun with those things that aren't compatible with P3D, but not all that much otherwise.