The main problem with the 16" Lightbridge is that the design has just been scaled up from the smaller models to keep the cost down - same parts, design, materials etc.
The problem is that when you double the length of components you get 8 times the flexure - and that's without any increase in weight, which is proportional to the cube of the aperture. In other words, if you double the aperture of a scope (without changing the design) you can end up with 8 times the weight combined with 1/8 the rigidity.
That is why some modifications (like replacing the springs, shimming the center bolt, reinforcing the tall skinny rocker etc.) may be required to get the scope to work it's best.
