Wow! Airbus and/or CX have really done it right this time. ( I don't know if SA or VS have the tail cam on their A340-600's which show on the PTV's)
With the wide angle lens on the top of the tail you could see the entire aircraft on the PTV.( except the tips of each wing). I felt like there was a chase plane following us to get such a view. To see your aircraft flying from a camera above was the most awesome experience.
At altitude over the Pacific you could see the curvature of the earth, even the contrails of the 4 powerful RR engines. Take off and landing could see the flaps moving, gear going up and down. Even able to see the other traffic in the area during takeoff and landing. And since everyone is sleeping/trying to sleep you don't need to open the shades to look out. Actually the view is better on the PTV than looking out the window.
100 times better than the nose cams that we've seen in the past.
Only problem, the crew should make an announcement to turn to Channel 49 to see this. I think I was the only person watching it.