You need look no further than the reviews for some of SMSL's products on Amazon to see that they ship products that are DOA and have early failures which are sometimes completely ignored by their iffy support. On the other side, Schiit actually stands by their products with warranties that are longer than most others in the industry. The only warranties I could find for SMSL's products are one year (with iffy support). The Magni's warranty is two and some of their higher end products have five year warranties.
The scratching noise you're talking about is completely normal for an analog pot, and it only happens when you're turning the knob. Third, the CNC machined enclosure of this SMSL headamp is so expensive to produce that it leaves way less money for the internal circuitry. The Magni 3 has a much more cost efficient but still very nice looking bent sheet metal enclosure, a fantastic balance of cost vs. looks from an industrial design standpoint, and leaves way more money on the bill of materials for the actual meat.
I've done a teardown of the Magni 3 myself and can speak to it's high quality internals including an Alps pot and Nichicon capacitors. From the looks of my splatter-free board, they've gotten much better about their production quality than they used to.