Just the right capacity, resolution and accuracy for weighing beans for a double shot.
Positive Product Points
Resolution to 0.1 gram, accurate, very small, portable, inexpensive, uses AAA batteries
Negative Product Points
Low capacity (150 grams / 5 ounces) so limited uses.
Detailed Commentary
This is a small scale, about 3x5 total. It's ideal for me to keep near my grinder, and the lid flips closed to keep grinds and dust out when not in use. The lid is held closed by a magnet, so easy to flip open and closed. It's also removable to use as a weighing tray since this is a pocket scale you can take anywhere with you. The weighing platform is approx 2.5 inches square. Since you are never to exceed the 150 gram capacity, you need to have a small, light bowl for measuring your beans in. I have a 39 gram stainless bowl that is just right for this purpose.
I've been testing and retesting and weighing all sorts of objects to determine consistency. I've found it to measure the same about 90% of the time, and the other 10% it is off by 0.1 gram either way. This is an insignificant amount for my purposes. It comes with a 100 gram calibration weight. This is usually right on the money, but occasionally comes up as 99.9 grams. An Equal packet weighs 1.2 grams almost every time. Once or twice it has come up as 1.3 grams. It comes with a little plastic holding tray. This usually weighs 7.9 grams but sometimes comes up as 8.0 grams. I think you get the idea.
Since I've been using this, my shots have been more consistent then ever. Now I am MUCH more able to tell the difference with slight grind or tamping changes.
Buying Experience
I used the oldwillknottscales.com website. I was looking at many 60 to 75 dollar scales that looked right for me. I used the chat function to talk to a salesperson, and told them that I needed a scale for espresso beans, so accuracy was important, I wanted 0.1 gram resolution, and small capacity. They said "hold on" then came back a couple minutes later and recommended this $24 scale which was about a third the price of the scales I was looking at. I got the shipping notice email within about an hour of ordering and it showed up 2 or 3 days later. Shipping cost was about $8.
Three Month Followup
Still love it. I have amazing consistency with every shot since I started using this, except of course, with a new batch of coffee, but then I know it's the coffee that changed so I can make a minor grind adjustment and I'm all set.
One Year Followup
Not using this would be a mistake. Now I even use it for pots of drip.