ACAIA 58mm Portafilter Dosing Cup (Medium)

Top notch quality. Definitely expensive. On drier days there is static.

This dosing cup does exactly what you want to do with it. It holds coffee beans very well and the retention is honestly not even that bad.
If you were to use really dark roast, you should be expecting 0.05~0.1g of grind retention but I'm not so sure if that much of retention is even something to fuss about in regular cafe context.
With light roast, I have absolutely no issue with retention.
Acaia dosing cup is definitely an item to passively "flex" if you have it on your table somewhere, especially if it can be noticed by equipment connoisseur and that is why it costs extra I think.

Sure it is overpriced as every Acaia products, but I gotta admit... the machining and stainless quality of this cup is SPOT ON! I just bought it for the hell of it and finaly it got into my daily espresso routine because first I had to put my bottomless filter on my (Rocket Fausto) grinder then guess the weight, put it on my Acaia Lunar scale and if needed put it back on the grinder's handle back and forth until I had the desired weight while now I can just unscrew the grinder's handle to save space, make a cleaner look, remove the bottom plate too as I get no more spill from having too much coffee. Instead I just put the Lunar scale right under my grinder, with tared to 0g with this cup so that when I grind it goes directly in it and I get the weight LIVE so I can always stop it before it overfills, or keep it further until I get the perfect weight. After I can transfer it fairly easily in my portafilter and do the rest. So... the reason I've knocked a star is the price BUT also that it tends to build some static and unless you want old grounds to be stuck at the bottom, you'll need to use ur brush and clean the inside and the top around the openning to remove all stuck grounds from the static so it's a few more wasted seconds but other than that, not a big deal.