Yeah the printers that use lasers are definitely more precise too. Here's a cool and simple demonstration of the basic principles for those having trouble visualizing.
And yes, the plastics used may not be the most solid, but people are working with new material all the time. Extruded nylon seems pretty promising... But like I was saying, I'd use it for a mold and make fiberglass or carbon fiber fairings by hand using the mold in my business fantasy.