The fellow that has that lift, has a goldwing and it never wobbles on him, and he used it to hold up a H-D dresser that got rebuild on that stand. Maybe the people where not a level surface when it wobbled or was confused with a little movement when they was tugging on it too hard. But I used it today to change out my kickstand and change out my oil, the lift was a rock, I had problems getting the spring back on and was pulling pretty hard to get the spring back on the kickstand foot. Bill Kratzenberg has the same lift he can tell you how good it is.
Some times user error can be the problem. I can also tell you with 100% certainness what is wrong most cars, a lose nut between the wheel and seat.