amazing post. thank you for taking the time to type it all out. ive read a bunch on grinders for the past 6 months. this is a nice concise primer that touches on so much of what ive been reading up on.

Jeff wrote: TL;DR -- If looking for "Mazzer-like durability", why not pick up a used Super Jolly and fit some modern burrs that suit your style into it?

(Be careful picking, as not only is the naming of SSP's burrs somewhat confusing, but naming of what is in the 64 mm size doesn't match what is in the 98 mm size.)
---

im fortunate enough to be able to expense some of the cost for work which makes the choice to buy new vs used more palatable. taking that in mind id rather just consider new machines for simplicity.

Jeff wrote: Both motor Watts and burr size are, for me, just numbers.

Peak power into the motor doesn't say much about how much power is transmitted to the shaft, or how much torque there is at grinding speeds. Most of the reports I've read around grinders slowing or stalling are around light roasts, such as those from North American roasters known for lighter roasts (Passenger, Onyx, George Howell's light roasts, as examples), European roasters that tend to the medium-light or light (such as La Cabra), or lighter (such as Tim Wendelboe). The darker the roast, generally the easier it is to grind the bean.

I resonate with this completely. but I have to evaluate somehow. like how audio receiver manufacturers "cheat" when they are advertising power while maintaining a total harmonic distortion threshold, it seems they all cheat in the same way (more or less). A question about torque ive thought about. wouldn't inconsistent torque cause variable rpm. I presume this could lead to a less consistent grind? how about those with the HG-1. if you dont rotate it at a constant speed, wouldn't that negatively affect the grind?

Jeff wrote: On burr size, great espresso can come from "lowly" 48 mm conical burrs. Terrible espresso can come from some 98 mm flats. For me, there seem to be a few categories of burrs:

* Classic flats and conicals -- most things from established, European grinder manufacturers intended for the home or small cafe market. These may be conical, 50 or 98 mm, or anything in between. Nothing special here and arguably in the same, general class in the cup as the better conicals, especially for "espresso" roasts and blends. Progressive manufacturers seem to be starting to "up their game" in terms of alignment and burr geometry and may have models in one of the latter classes.

just to confirm, what are the progressive manufacturers? the start ups? if the boarder was open, I think id order a eureka KR on amazon for $1000usd to an amazon locker, drive across the boarder, pick it up and be done with it. a 68mm conical from eureka can't be that bad for that price. read a bunch of bad things about the macap m7d. short of being able to get niche, for conicals it seems like it jumps quickly to the Kony/key/e10 range. which id spend on, im just thinking would I not get value out of a bit of a cheaper flat? im a bit lost here I guess. if I enjoy a mouthy feel to my espresso, does this mean I might be happier with a conical?

Jeff wrote: Past this point, my opinion is that whether the in-cup quality is "better" depends a lot on your choices in coffee and style. Some favor clarity, brightness, sweetness, smoothness, ... No grinder that I know of provides them all, at any price point.

* 64-mm class, modern burrs, well aligned -- Depending on who you talk to and what they like, these can be a step up in one or more of those characteristics. It can also be a disappointing experience if you favor classic, creamy espresso, especially if you've got the "wrong" burr set for your tastes. Here you're starting to get into the current trend/fad of narrower particle distributions and, often along with it, needing to move away from the classic "36 g in 25 seconds" style of shot. A lot will depend on the burr set chosen.

* 80-100 mm, modern burrs, well aligned -- Here you're deeply into personal preference. Even some of the most opinionated on grinders have been known to embrace burr-set X one month, and consider it unworthy the next.

thanks for the info. I think I get the gist of what you are saying. so let me ask you this. if someone gifted you a K30 or E8 for free. which would you pick. more or less same price but different burr sizes. guess you are saying doesn't matter about the burrs/specs, they mean nothing until you can taste it in the cup?

Jeff wrote: I don't know that slight (tiny) variations in rotational speed impact grind uniformity a lot. It is clearly a problem if the burrs stop, which has been reported to be the case with some grinders and lighter roasts.

Thank you so much Jeff!