Mazzer Mini Electronic
At the time of this report, the Mazzer Mini Electronic Doserless carries a hefty premium of about $200 more than the doser Mini. Besides a nice funnel and portafilter cradle, what else are you getting compared to the standard Mini? Looking at the specifications, the features that stand out are the 64mm burr set (same as the Super Jolly), two programmable precision dosing timers, and obviously the doserless-ness.
Although the Mini E's motor is driving larger burrs, the housing is the same size as the standard Mini. The exit chute of the Mini E is subsequently shorter, leaving a very small ledge for grounds to collect. Running the grinder for a couple seconds at the beginning of a session ejects stale coffee remnents.
The Mini E consistently delivers the grinds to the same spot, which is great for neatness, but you'll need to work the distribution. I set the dosage setting to nine grams, redistribute halfway, and then tap / redistribute a second time before tamping (normally I rotate the portafilter while dosing with the standard Mini, but wanted to try out the Mini E's portafilter rest).
To see how consistent the dosage amounts are, below are the recorded weights for a series of shots (two presses of the single dose each): 18.0, 18.3, 18.3, 18.5, 18.1, 18.8, 18.8, 18.8, 18.9.
Not enough data points to be statistically valid, but suggests that there's a variance of about ±0.5 grams. That's pretty good for a timer and the consistency of the half dose + half dose approach coupled with standard volume dosing makes it easy to improve accuracy to 0.3 grams or less. The dosing is by way of a precision timer, not weight, so the actual dosage will vary depending on the beans; softer coffee will grind more quickly and the dosage will increase. Despite the variance, it is easy to use the Mini E's dosage adjustments as a very close "ballpark" weight and then refine the dose to the last smidgen using traditional basket-leveling volume.
Warning: The doserless Mazzer Mini has a substantial finger guard and wire grid covering the exit chute. Do not remove them! And especially do not remove the wire grid. It is imperative to dispelling static so the grinds fall nicely down the funnel. See The Bench comments for a full explanation.
Since the dosing controls are what distinguishes these two grinders, let's zoom in on them, starting with the Type A control pad atop the doser funnel, as shown in the photo above on the right. The purpose of the one and two cup buttons circled in red is self-evident; the smaller "hand" button is a momentary switch. Pressing and holding it runs the grinder, releasing stops it. Pressing the one / two cup button runs until the end of the cycle unless you toggle the main power switch. The control panel acts as a lid for the doser funnel and is tethered by a "telephone cord" to the grinder. Such a wire would be a prime candidate for abuse in a busy café, but shouldn't be an issue in a kinder domestic setting.
The dosing adjustment is set by turning one of the two screws (single and double espresso), as shown in the photo below. A turn of 180 degrees corresponds to approximately 0.5 grams of coffee.
Dosage adjustments for Type A and Type B
Looking to the grinder on the far right, note the indicator lights. The Type B has a single push-type switch between these lights in the place of the Type A's screw shown on the left; you start the dosing cycle by pushing the portafilter against the switch, conveniently using only one hand. Tapping it once selects the single dose (one cup indicator illuminates), tapping it twice selects the double dose (two cup indicator illuminates). The same switch acts like the momentary button on the Type A's (the hand button shown earlier). That is, press and hold the Type B's push-type switch instead of releasing it immediately; the grinder will run and the dosage indicators will flash to make it obvious it's in "momentary grind" mode. Very nice!
Since the Type B uses a push-type switch, there's no need for a control panel like the Type A's atop the doser funnel. Subsequently the Type B's funnel lid is an ordinary plastic cover, same as the standard lid for the Mazzer Mini.