Time will tell if this thing holds up but I'm impressed thus far. It's quieter and quicker than my previous grinder, the fellow opus, which died after 3 years of daily use.
The DF54 is a substantial machine with serious heft, and appears to have a solid build. I've tested a variety of beans, from light to dark roasts, and it's produced really great tasting espressos. So far, so good.