Side Note on My Post: I do like to caution that even though I'm presenting the photos I shot as perhaps evidence questionable product delivery quality...well, anything you see magnified to a great enough extent will start to show flaws (or what are seemingly flaws). Too much magnification can be unfair to just about anything.
But on the flip side of that, all I'm showing is "macro" and not "micro." With micro, we might start seeing things we wish we had never seen. But with macro, it's not much different that looking at something through a good magnifying glass. It's not that I'm purposefully trying to make a product look bad, but just showing what I saw when I took a closer look (that is, via a macro lens).
When it comes down to it, long-term, everyday performance is the key issue. I'm sure I'm going to be a very happy Mazzer Mini owner over the long haul. But there is still a level of disappointment in the seeming surface quality of a rather key replacement part, if you understand where I'm coming from. But if those initial impressions of surface-level quality don't really affect long-term performance...then maybe it's not such a big deal. Transitory disappointment on the road to long-term happiness...

. . .
But, too, the things revealed with even moderate magnification are not things we'd notice with the naked eye. One might be tempted to attach the new burrs and start grinding away. Even though I got no caution or warning from the vendor or manufacturer to "clean before using," I'd sure recommend that anyone who obtains new burrs for a machine run them through some kind of cleaning process before use. Sacrifice some rice or beans or run some Grindz through the new burrs (or use something like I did: air compressor blower, toothbrush, and Grindz).
Just some further thoughts.
