"with all respect two weeks of dedicated work will not reveal all the possibilities of a keyboard, although you would have the answers to your personal needs."

Oh I agree 100%. The shortest time I had any of these boards was the Korg PA800, and that was for several months. My point was, you have to spend a LOT of quality time with a keyboard to become familiar enough with it to see whether it will work for you.
I've had the SD5 for about a month now, but previously had X1, SD1 and Midjay (twice), so I was already familiar with the inner workings of the OS.
DonM