Exactly this. Also, the instability means the keyboard is more forgiving of small aim mistakes. If my finger presses 10% of the wrong key and 90% of the right

Exactly this. Also, the instability means the keyboard is more forgiving of small aim mistakes. If my finger presses 10% of the wrong key and 90% of the right one, key stability on the corners will mean the keyboard registers both. On the 2015 keyboard it only registers the one I meant. The fact that it wobbles also gives my fingers an extra milisecond to adjust position if it feels it's wrong. It's also more obvious when I did hit the wrong place and I can automatically reach for the backspace/delete key without even thinking or noticing the wrong key visually on screen. It's overall a more fluid typing experience. This is especially useful when I'm typing at night or if my fingers are not moving optimally - like when they're cold or otherwise tight or tired.