Yep, mine is a production machine, rather than a "prototyper". It is designed to run 24/7 more or less, so all metal construction is a must.

The snag with breaking bits as you assemble your printer is that you need the complete machine to print a replacement part. Did they send you a replacement for the z axis motor mount? I built my first Huxley from a kit, and some of the printed parts were a bit fragile. The hours I spent making and shaping bits of aluminum really made me appreciate being able to 3d print. It is still my prototyping printer, so it has since been modded, pimped and remade.

They are doing some pretty clever things with composites: http://3dprint.com/31546/impossible-objects-investment/ , so if you can use the right materials breakages can almost be eliminated. Damping vibration might still an issue with printed parts, but I am quite interested in metalic fillers like this mob are doing: http://3dprint.com/23239/gmass-filament-metallic/ . I am so going to get some and have a play.