I currently have a Tyros 2 and a Pa2XPro sitting side by side. I turned the volume right down on both of them and played the keys softly, heavily, and in staccato fashion. The noise from the Tyros was very similar to that on the Pa2XPro. If anything the Tyros had a thud at the end of the key stroke which was not present on the Pa2X. I don't see or hear any quivering on either, the keys come right back to where they should be.

I had never noticed the noise on the Tyros before even when playing quietly in church. IMHO, this is a non-issue on both keyboards.

Graham