The construction of this thing is as rock solid!
However, my Macbook Retina 13,3" laptop does not sit perfectly. This is because of the plastic support-pieces holding the laptop is fixed in its (slightly curved) position, and are unable to flex. The result is that the laptop is able to slide from side to side, since the support-pieces are not reaching the corners.
Also, you need to place the stand facing directly at you, since it is not able to be tilted sideways. This is not unusual when it comes to stands, but still; it would be a nice feature.
As far as stability goes - it ain't.