I actually have several of these arms in use. I have a 34" monitor above two 27" monitors. Therefore, I needed a total of 3 desk mount arms on the office desk to get the appropriate height. There is no wobbling and I can move the monitor wherever I want. I am fully satisfied with my "construction" :-)

It depends on what you mount the bracket on. I have a wall mount with this extension, and I have no wobbles with a (rather heavy) 27" monitor.
But I can imagine that it would look different with a desk mount.

sorry, wrong product.