Hello Pratzert,
The KN7 is so easy to use. Once you've made your choices, wherever you save it to, be it on-board, SD or floppy disk, it will stay exactly as you saved it until you manually make any changes and even then, it will accept the changes without any fuss but with the Yamaha, you have to decide whether it's a style, then choose voices and whether you need to save other parts as well (such as the OTS) and finally where to save the finished song - either to Styles or Registrations. This is fine if all you want to do is play your own pieces, but should you decide to make major changes, or use a third party style, you must make sure you give it another name or else it will overwrite the whole of your original piece and even changing the 'icon' can prevent the keyboard finding it when needed. Whereas the KN7, always finds any version quickly either by name, number or PMs. I find the Yamaha keyboards involve a great deal of button pushing taking up a lot of my time which I would rather spend actually playing.
With regards to the possibility of a Tyros 5 coming soon, as the latest pianos have a 'touch screen' I suspect the keyboard will go down that road also. I hope not, for 2 reasons:-
1) I like playing quick tunes such as Tico Tico and boogie so for me it might be impossible to play at speed and as well as tapping the screen to make any changes.
2) I also use music books and sometimes they need a quick flip-over of the page(s) which also means taking my eyes off the music and frankly even now, I sometimes lose sight of the notes I should be playing when doing this. Also age is catching up with me and I find I cannot move as quickly as I used to so imagine playing Tico Tico, tapping the screen for something or other and also having to turn pages..... it could become quite comical couldn't it?
Still! as the saying goes "Leave 'em laughing"
Audrey