I purchased a triple monitor stand recently and was a little shocked when I mounted my monitors. My two very similar Samsung monitor models had two very different locations where the VESA mount was located on the back of the monitor. The result, I can't line my monitors up horizontally on the Ergotron arm. There is about 2.5 inches different in height! Both monitors were 21.5 inch size, but one was a slightly newer version. The result is disconcerting.
It would be great if there was a simple adapter plate that could be added to adjust the vertical height of different monitor models. Should be pretty easy to design.
This must be a common problem for individuals like myself, who eventually replace a monitor and can't get the identical model again. Or for those who wish to add a second monitor and Ergotron arm to their existing single monitor setup.