I gave biltong a second try with a better cut of meat, in an attempt to make it more authentic (and tastier).  I used a 3-pound eye-of-round (same cut as often used for bresaola), and cut it into three 3/4" slabs running with the grain.

Then, I dipped them in cider vinegar, added the spices (toasted corriander seeds, brown sugar, salt, and black pepper), and put them in the dehydrator.  It's been about a week since I actually did this, so don't recall the exact times and temperature, but I think I let it run for about two days at around 120F degrees (with the idea of low and slow, compared to my last approach with the thinner strips).  Here's what came out:

It felt pretty good on the outside, but the inside was still quite moist, and I was concerned that it might spoil.  It also looked a little too moist/rare when I compared the interior to lots of biltong images online.  So, back into the dehydrator for another day, and at a higher temperature (150ish, I think).  Here's the final product: I need a south african to drop by to taste it and confirm, but I think it's done.  It tastes great (and gives a good jaw workout).