The mouse...
...almost never works - on my 14 international flights in the past 9 months, I believe the mouse has only worked once or maybe twice. I have mentioned this to the FA and even service director a couple of times and they have told me to simply use the touch screen, almost as though they do not expect the mouse to work. Not a big deal but when reclined the touch screen is a bit of a reach...
I find that in general the "new" XM interiors are starting to look pretty tired, I guess they have been around about 3 years now but the wear and tear is really starting to show.