Is not really that important, but I still wish to clarify..
...Various users have reported in the past that the keyboard "rattles" when playing normally. In most cases this is probably because the black keys beat against the white keys when playing. ...
No, rattling doesn't happen because black keys would
bump against white keys -Yamaha has taken care preventing that to happen. However, now it's exactly that solution that causes rattling.
If you take a look on
this video (pause at 7:16), then you can see that keys have left/right limiters (L-shape on the bottom of key) -this limiter goes into the slot on keybed baseplate. Yes, that way it's prevented the keys to bump into neighbor keys, however now key bumps inside the slot on keybed baseplate. And to dampen that rattle sound, Yamaha decided to put a small amount of grease into each slot. Obviously, over the time the grease is pushed out (as we play) and we hear rattling again.
I simply can't believe that some engineer decided for this solution... is embarrassing. Other than that, I quite like the feel of SX700/900 keybed (as long it's silent).
But there's no doubt that Genos keybed simply feels better.
Btw. I have no problem with rubber buttons on panel: they're reliable, give good feedback at pressing, they're are silent and impossible to break. Yes, Genos buttons look more fancy
Bogdan