Is a built-in grinder good enough, or should I buy a separate grinder?

This is the most consistent point of friction in r/espresso threads. The integrated grinders in the Barista Pro, Express, and Impress are described as good enough to make great coffee for most home users, but enthusiasts chasing light roasts and very fine dial-in routinely recommend pairing a grinder-less machine (or ignoring the built-in one) with a dedicated burr grinder like a DF64 or Baratza.