I've owned a few home grinders, four to be exact, and I've used many more. I've owned the Capresso Infiniti (wasteful), Baratza Virtuoso (overrated), and Baratza Preciso (fantastic). The latest addition to the household is a Porlex Mini, which I picked up from from a shop in San Francisco, one of the few places that currently sells them. They call it the best manual grinder on the market (owners of the OE Pharos might, at this point, prepare a rebuttal) and, seeing as how I was in the market for a manual grinder, I decided to pick one up.
I don't know who, if anybody, reads this blog of shaky-handed obsession. In the interest of including everybody, let me say a few words about home grinding. It, along with fresh whole beans, is a key part of the home brewing equation. Burr grinders are best: you want something that will grind evenly, will grind without producing much dust, much waste, much heat.
The best home grinder I've used is the Preciso. I think you'd have to spend hundreds of dollars more to get something better; essentially, to do better you'd have to buy a heavy-duty professional unit, not that the Preciso isn't up to professional requirements: some bars, Noble Coffee among them, have used them in their shop to great success.
For me personally, coffee never tastes better than it does first thing in the morning and the Preciso, while quiet for an electric, is still loud enough to disrupt sleep. Hence my interest in the Porlex.
How does it grind? Pit a medium-coarse Porlex grind against the Preciso's and the difference is obvious. Despite the Porlex's spring, which apparently helps some with burr stability, you do get some larger chunks (at the end of the grinding process, when the burrs are less stable) and the grind is nowhere near as uniform as it is out of the Preciso.
But in the cup? I would have a hard time saying that my Porlex cups are categorically worse than my Preciso cups. My Preciso cups have better body but my Porlex cups often give me more flavor nuance. Edit: after some more testing, it's become much more obvious that the Preciso's is clearly better. But, it's not like anyone reads this, right?, so I doubt I inspired any uless than ideal purchases...
So if you just need to grind 20 grams quietly--or if you're on a budget--I feel like a Porlex is a fantastic choice. It's not just a travel grinder (although it can do that admirably; in fact, it was designed to fit inside an Aeropress chamber); it can do as a primary home grinder, just so long as you don't need to grind large quantities. Grinding 20 grams takes about as long as my electric kettle requires to boil 5-600 mL. (Note: I grind for drip, not espresso.)
It costs twice as much here (~$70) as it does in Japan but it's still a nice buy.