Eikka

The reason why the other printers are heavy and cumbersome is because light spindly parts may look nice and cost less, but they lack rigidity. Any stress will deform the structure and put off the accuracy of the machine.

For example, they're using what's known as a bowden extruder because delta-arms can't deal with much inertia. The filament is pushed through a cable sleeve by a motor fixed to the frame, so the platform only has to hold the nozzle. However, the cable sleeve is quite stiff because it's under internal tension by the motor and filament, so the delta arms are met with variable forces that depend on how the cable happens to run at each position of the platform — and since the system is not rigid they'll always have problems with displacement and accuracy.

They're also limited in working volume by the size and cost of the unibody extrusion frame. But, for a cheap desktop printer it might just do. The first affordable inkjet printers were quite crap as well.