Look at the Carbide 3D support structure. Skinny little supports, probably aluminum. If that could hold a tolerance of 0.001in cutting steel I'd be surprised. Now look at the cast-iron frame of the machine van Vark uses, and the size of the slides. Rigidity requires a bulky machine. That's needed for those beautiful smooth finishes.
Haas, which is a serious milling machine manufacturer, sells one of those little desktop things for training use. They rate it for machining plastics and machineable wax only. The Haas mills for metal start around US$40,000, require a serious concrete floor, and have serious coolant and chip removal capabilities.
My toy in Canada was an old Excello, it was roughly the same as a Bridgeport from the 70's, great machine but not practical for 'home' use. I agree that for serious work you need something solid, but then again, at that price I don't think it would be realistic to expect that degree of stability, this clearly looks to be designed for very light duty, steppers not servos, little belts driving the spindle, lots of aluminum.
I also had a big Cincinatti wheel mill, that thing was stable. And so heavy that we never even bothered bolting it to the floor.
Haas, which is a serious milling machine manufacturer, sells one of those little desktop things for training use. They rate it for machining plastics and machineable wax only. The Haas mills for metal start around US$40,000, require a serious concrete floor, and have serious coolant and chip removal capabilities.