I'm glad I reach this post, though it's quite late to be informed. LOL. It's good to be confirmed that some of the PMDG's plane will be available to X-Plane 10. I'm currently running FSX and just brought X-Plane 10. Yes, I see nothing exclude the airport of Seattle and the cloud. As someone said X-plane is still in beta version even they sold a retail box of it. Before reading your comments in page 1 to 8, I did't figure out why I don't like X-plane. But now I know, their user interface is a problem and lack of add-ons. But they do have a great dynamic light especially in night landing, you'll see the different, and the cloud rendering. As Austin Meyer demonstrated on Youtube, you will never see the see the same cloud ,etc etc again. I'm planning to get a Prepar3D in this weekend. It's properly a robust and potential platform to perform more than in FSX. At least, they'll continue working on it. I'm new to flight sim, if I said something you don't like, I would like to hear what you think and please forgive me.
Best wishes,