This is unfortunate. I was hoping you would've received Rev. B
of the 7Series where the production line would have made
some modifications to correct the problem on the assembly.
Obviously not the case in your case. Perhaps your repeated
calls forced them to pull one from old inventories due to the
delays?
This reminds me of a time when I read about people who bought
laptops or LCD displays and found bad or stuck pixels. Very
insignificant but there. Manufactures say 1-2 pixels is 'normal'
in terms acceptable level of quality control. The flecks of dust
is more about QC than a generic 'defect' and because of the
isolation, the cost of salvaging a few of the afflicted vs. a core
production modification might not be warranted or justified.
ie. a business decision.