A few bits after a week with the Vario:
I didn't notice any during the test. But over the next few days it got worse and worse, regardless of coffee or humidity. I removed the burr, emptied out the grind chamber, which held around 2.5 grams of coffee, reassembled, and the static was gone. By a few days later, it was back, and I had to repeat the procedure. So cleaning the burr chamber is a temporary fix.
Bit of mystery here. The burr chamber had around 2.5 grams of grind in it when I cleaned it to control the static. Yet the very next time I used it, putting 15 grams in got me 15 grams out. So where is this waste coffee coming from? I'm guessing the grind area slowly, but progressively, gums up with ground coffee, and at some point the grinder's performance suffers. It may be that the grinder needs frequent cleaning to keep it at best performance levels people have observed, and that if one doesn't, the performance drops to the mediocre levels others have observed.
A Second Look at the Burrs
The Vario's burr set doesn't look particularly good. Here is a comparison against the Mini:
Using the measurement technique I used to for the Titan Grinder thread, the Mini's burr length is 7.1mm, already rather small, while the Vario's is 4.3mm, which is a miserable number, smaller than the tiniest peppermill or hand grinder. But in the taste test, the Vario beat the Mini, and this is a result I stand by. So what gives?
A second look at the burrs shows that the angle of the Vario's burrs is much more offset, while those on the Mini are much more along the radius. So while the Vario burrs only take up an annulus of 4.3mm, whereas the Mini's occupy 7.1mm, the longest Vario burr is 10.5mm in length, while the longest Mini burr is only 10.0mm in length.
Does this matter? I think so, and I think the measures I gave during the TGP may be inaccurate because of this. The beans are forced from the inside to the outside of the burr plate by the ridges. If the ridges are relatively straight, a small turn angle forces the bean from one end to the other. If the ridges are as oblique as the Vario's, a much larger turn angle is required to get the bean from inside to out. In other words, by putting the burrs at a very oblique angle, Mahlkoenig created a slightly longer grinding path than the Mini's while using a smaller burr.
I think this partly explains why the Vario performs as well as it does, despite the small burr size.