Update:
Just finished doing this to my 55g 87U. I can definitely feel the key shortened key travel on this, although, in a way it's increased the tactility slightly. Still feels soft an buttery smooth. I don't think it's going to be a deal breaker for me, as I prefer shorter throw switches generally. There's huge difference in noise though. Super, super quiet. The 660C still thocks louder though. I'll try to get a video of the 55g 87U up soon.
*EDIT*
Okay this is driving me insane. Taking it off the RF...