After using the M4 for daily use over the last three months with a variety of coffees, most lighter roasted single origins, my final thoughts and additional findings are posted here:http://www.meticulist.net/versalab-m4-single-dose-espresso-grinder-review
It is very much a follow up to the initial review also posted in this thread and linked here: http://www.meticulist.net/blog/versalab-m4-grinder-first-look
I'm posting this here because I'm now labeled as a "vendor" per the discussion in this thread: Vendor participation in the forums. What about their friends, insiders, promoters, and influencers?
which is a different discussion, which regardless of your opinion on that topic, I maintain that the findings and opinions in all of these linked posts are my own, completely independent, and I have disclosed my relationship with Versalab and provided transparency throughout all of these posts.
And to summarize those findings and opinions: simply put, the M4 is a complete game changer in my opinion.
It's the only single dosing grinder that doesn't require any additional tools or steps (RDT, funnels, transfer of dose, WDT, grooming, etc.) to pull perfectly even shots with any coffee. It has the ability to be hopper fed through volumetric dosing, fully capable of any commercial environment, even with two different beans. It is extremely well built and aligned with superb manufacturing tolerances. And if high extraction yields are your thing, yeah it's capable of those too.
At the end of the day, the M4 feels like it hits a sweet spot for:
home-friendly footprint with very little mess
simple workflow (the most simple?)
shot profile and mouthfeel that has the depth or thickness of a big conical
with the ability to hit 25% EY's of a big flat
I'm just not sure what else you could really ask or hope for. For me, it doesn't have any shortcomings, and I haven't been able to find anything I would want a grinder to do differently.
Unless there's a next wave or breakthrough in technology that unlocks further extraction or some other secret we haven't figured out quite yet, I'm finding the M4 might just be single dosing grinder perfection.
Please let me know if you have any questions or would like any clarification on anything. Thanks!