I haven't been on the Jade, but was recently on her sister ship (Pearl). I believe the layouts are virtually identical. Like you, we really enjoyed sitting by the window at the back of the ship (I guess I should say stern). On the Pearl, it was most definitely first come, first served. That worked fine for us, because we tend to eat breakfast and dinner when they open. Get there a few minutes early and you're good to go. If DD and DW aren't quite ready in the morning, I just go down by myself and enjoy my (first) bloody Mary and some morning sunshine.