Interesting.
Do you have any thoughts on composite-based aircraft like a Cirrus and flutter? A few times I've had a Cirrus SR22 into a pretty steep descent with poor controller sequencing for an approach into busy terminal space and had to push it down, but the plane felt solid even at 180-190kts TAS. I backed it off only because I get nervous with any unexpected turbulence which is not uncommon in Florida.
The Piper Saratoga I flew for a bit didn't seem to like the speed as much, that or the toga was a bit more vocal than the Cirrus in what it was feeling with regards to airspeed.