We do know from video broadcast that the rear edge of the floors of both cars do rub the track in high speed corners.
The Mercedes uses an edge blade and the RedBull uses the ice skates to maintain the airgap between the floor and the track.
The RedBull has a high static ride height though espeially at the rear. We know this from Pit Lane photos. So certainly it is softer sprung than the Mercedes and can also ride kerbs better.