We have two with the samsung (no holes in tray) and one euro launch unit with the hitachi (holes) and the hitachi is considerably louder just like llamma concluded here months after we already knew this.
The samsung is a hiss where the hitachi has a distinct rawwwrr to it.
Now, that said, people should compare them in both vertical and horizontal position since to me, both are louder in vertical (the unit rumbles more) than in horizontal, for whatever reason.
Does an imbalance in the labeling or molding of the disc travel so much faster down toward gravity than it does up that causes this rumble? Or is it infact the more stable position and wider spread of the weight of the unit in horiz.