IMPORTANT NOTE FROM LM - "Prepar3D v3.2 will no longer be available from Prepar3D.com."
If you DO NOT have your old V3.2 download, you may not want to try the V3.3 Client upgrade yet.
First - I only installed the new 3.3 Client, not the full instillation.
The only loss was the calibrations. All other settings were kept. What a huge difference from the V2.x days.
When first run, Prepar3d V3.3, will take some time building new files, especially when you switch aircraft or inside/outside views.
During this time you'll see some odd screen images. Don't worry. After a certain point this will stop and everything will work well.
There's something that I can't put my finger on but, to me, the 3D environment seems to be more realistic in it's passage as I fly over, and around the scenery. Not the scenery it's self, but the overall environment.
I know that doesn't make any sense, and it may not even be real. But the act of flying "feels" better in some way.
There's a lot of changes, many that'll be unimportant to most people. Read the change logs and explore a bit.
You'll find View Group Management under Views. If you have three or more monitors, this might be a major improvement.
I haven't played around with it yet, but for anyone who's interested - Display And View Group Configuration
FROM LM - "View groups allow a large field of view to be distributed across multiple displays by assigning a view to each display. When a view group is active, it can be controlled by any of its members so that a group of displays behaves similarly to a single large display."
Personally, minor problems aside, this is a great improvement. And if V3.2 is working well for you, the client upgrade is the way to go.
If you feel the need for a full upgrade, you might want to wait a bit.