I've noticed that fullscreen mode is per screenset, shouldn't it be per project or do some of you want some screensets in fullscreen and others not?

Maybe I'm missing the point (not for the first time) but what difference does it make?
 
No matter which screenset you are working in, F11 will toggle between Full Screen mode and your current screenset

 I guess the difference would be 9 presses of f11. I noticed ths too, and consider it a minor perplexation.

Maybe I'm missing the point, too, but if you want the whole project shown in full screen mode, I assume you always pressed F11 after opening the project in X2a and saved screensets as necessary while you were in the full screen mode (which I did). Now, in X3, you no longer have to press F11 after you open the project, and all screensets are shown in full screen mode. It's like heaven to me. In fact, it's one of my top 3 improvements in X3, although it's not even mentioned in the fix/improvement list.

 No really big point at my end, just would have expected fullscreen mode to be global, not per screenset. I have a template I use with my screensets ( great feature by the way) set up how I want them. Sometimes I wanna see the takbar, sometimes not, and which screenset I'm on at the time doesn't affect wether I want to see the taskbar or not. Again, no biggie, just couter-intuative( to me) behavior.