I'm a relatively new owner of an OX CNC (Ooznest kitset). I also researched a bunch of other options before purchasing, including the Shapeoko 2 & 3. I've spent ~$1200USD (incl. shipping literally across the globe), Those in the US could easily come in under $1000USD. The above mentioned CNC routers are really on the low end in terms of minimum required rigidity.

While the feed rate of the machine looks OK, but they do not specify the depth of cut per pass. Combine this with the fact they don't show a part being cut from start to end, even speed up, is telling. I suspect a excessive number of very shallow cuts, leading to long cut times and excessive tool wear. I also suspect if the cut depth is to great you might find out the true meaning of climb cutting.

0.4mm resolution is not that great and the resolution actually changes based on how far you are from each motor!

Mounting material to cut on a vertical surface is going to be a major pain if it's not a quarter sheet of ply or bigger. And once a part is cut loose without tabs the router is liable to kick them out, that's going to be a nasty learning experience for some.

The only great things about this machine are its large cutting area, small foot print and low price. But fair warning, the limitations will start to stack up fast I suspect, this machine would be best suited cutting flat pack furniture designs from full sheets of ply, when delivery time is not an issue. To his credit this does seem to be the market he is targeting.