I am a little late getting out of the starting gate with the FSX demo, which I sadfully found out about last night :-[!
My first impression is that Microsoft has given creators much better tools to work with to create a more realistic Flight Sim world both on land and at sea. But I haven't really cracked that baby in yet.
My first demo flight was at Princess Juliana. My first impression doing a day flight was the water didn't look as impressive when looking straight down into it. Howeever when skimming the waves you notice the reflections of the mountains rippling off it, which was cool. Any reason why it doesn't look that way from whatever angle you look at it!
Can you start importing some of the FS9 planes into FSX like the F14 tomcat and the F16 Falcon? I notice someone import a mig 29 although it didn't seem fully displayed in FSX.