Grind quality is the first criterion that actually shows up in the cup. Conical burrs tend to lean into a heavier, rounder espresso with a bit more forgiveness; flat burrs often emphasize clearer separation and can feel more precise once dialed. The Eureka Mignon Specialita uses 55 mm flat burrs, and that size—paired with stepless adjustment—is exactly why it produces espresso that doesn't swing wildly between almost there and what happened.
The Baratza Encore ESP and Fellow Opus both use 40 mm conical burrs, which can absolutely make excellent espresso, but they hit their ceiling sooner when you're chasing very narrow recipe windows. The Encore ESP is the rare grinder that makes sense for beginners because it's designed around espresso resolution where it matters, yet still stays simple. At $199.95, it's also one of the few legitimate espresso grinders under 200 that I'd recommend without a long list of caveats.
The Opus is impressively capable across a wide grind range; its big win is keeping the workflow approachable for people who bounce between espresso and other methods. The trade-off is that the Opus's adjustment system can feel less straightforward when you're chasing tiny espresso changes—you may need to be more methodical and take notes.
Workflow—specifically dosing and retention—is the reason single dosing has become the default for a lot of home setups. With the Niche Zero, the headline isn't just its 63 mm conical burrs; it's the way the whole machine is built around beans in, grounds out with minimal fuss. It's stepless, it's fast to change settings, and it's unusually easy to live with if you rotate coffees.
If you like the idea of single dosing but want flat-burr options and a more platform mindset, the DF64 Gen 2 is the pragmatic choice. It runs 64 mm flat burrs, and the real appeal is compatibility: many third-party burr sets exist in this size, so the grinder can evolve with your taste. The DF64's honest drawbacks are also part of the deal. It's more of a hands-on routine: a bellows purge is commonly used to keep retention low, and you may spend more time cleaning, aligning, or tweaking than you would with a more appliance-like grinder.