The standing desk I have is super solid, I went onto alibaba and ordered two frames directly from the manufacturer, in total I paid about NZD$300 including shipping for each of them, I bought a benchtop, put a nice edge on it with a router and then oiled it. currently have a 27" imac and a 27" monitor on a vesa mount and no wobble whatsoever. I highly recommend going this route, far cheaper than a premade product. The electronics are a bit chinese, but they work fine.

edit: just looking at the uplift desk, I think it was the same manufacturer they use, as my frame looks exactly the same, and the weight loadings are the same.