I think the points made in the article are good, but the assumptions about manufacturing are quite a bit simplified. I know I might seem like the stereotypical engineer/SLR hobbyist who is way too technical about camera gear, but I work in the medical device manufacturing industry and have a pretty good understanding of how tolerances are set and how quality is ensured in the product. Yes, subcontractors are involved in any lens manufacturers supply chain, but in the end, Canon has to either validate that the manufacturing processes will always meet the spec's, or they have to audit the parts, inspecting them to their specification. So in the end, it is still the lens manufacturers responsibility to ensure sub-component spec's are met. Additionally, even though individual parts have tolerances that can stack up, designs can be used that mitigate those effects and the final lens assembly can still be evaluated as a whole (I remember seeing in the "how it's made" Canon video that the 500mm lens was inspected using interference fringes that can measure much smaller than 2 microns, I would imagine). Anyway, in short, I appreciated the article, but I think lens manufacturers can still design quality into their parts and final products no matter who makes the components. From reading reviews on TheDigitalPicture.com, it seems third-part lenses often have more trouble than Canon, which is probably a quality issue over fault with their designs.