3D Printing for Validation Testing and Production

I am fascinated with 3D printing. Up to now I have not been able to determine if 3D printing has broken through to being used in actual design concept validation testing or in actual production of a volume part.
In my industry we obviously use 3D printed parts to get a 'feel' for how a part will handle and assemble. But, given advances in printing technologies is anyone taking printed parts further?

Sheffield Engineering produced a small video describing their latest technology for producing plastic parts. Sheffield produces layers of plastic powder with carbon black integrated into the material.  The carbon black acts as a heat sink for the UV light, which melts the plastic.  Sheffield states that this method allows for fine tuning the amount of carbon black in any section which modifies the heat input and the subsequent material properties in that section.  Density can be adjusted up to 40%, for example.

An article by "The Engineer" at Engineering.com has further detail. One quote caught my eye:

Although still in development, HSS already holds great promise for industrial use as the process can be scaled to work at comparable speeds to conventional high volume processes, such as injection moulding. 

Really?  I am not discounting the possibility, However, for high volume products, could HSS (high speed sintering) be cost effective?

And what about potential failure modes for this process? For injection molding you have to control time, temp,, humidity, pressure....   For HSS you need to have confidence in the amount of carbon black infused with the plastic powder.  How capable will the printer be over time?  How well with the metering be maintained between the beginning and end of the shift?  I think the PFMEA for this process would be an interesting exercise.