I tried a low cost one whose name had better be not mentioned. It came as a flat pack and required assembly, but the materials of which it was made were such as to give a 0.1 turn span between a screw not being tight enough and too tight so the material cracked.
When we got it to work, the plastic it extruded didn't really want to stick to the base, so the model tended to come loose in areas and warp. Altogether it was a hell of a lot more trouble than it was worth.
Windows 7 ultimate, Core i7 3.07GHz, 4 cores, 9G memory GEForce GTX 285