The Gleichdick grinder from Austria has been mentioned a few times in this thread, but I haven't seen anyone sharing personal experiences with it, so here we go.
So the Gleichdicks (bit of a funny name in English, isn't it?) are made out of hardened (300HV) aluminum, they come in 2-, 3- and 4-part variations, different sizes and colors, there's also a wood version (with an aluminum mill) available. Their main goal was to create a device that is able to grind fermented weed, which is known to be very sticky and moist and will get squeezed and torn apart by most other grinders.
I use the 2 part versions, because I prefer to finetune the grind for each session instead of relying to preset grinds from a plate. The shape of the Gleichdick is indeed useful when working with very dense buds, it also helps a lot in case the pieces are jammed. All variations have no threads, the pieces are held together by magnets only. Handling it feels natural and is effortless. The manufacturing is well done, everything fits together nice and smooth. I also appreciate that it gives me enough room to put my herb; many grinders have dozens of blades and teeth which require breaking down buds prior to the actual job.
I clean my grinder regularly, so I can't claim it doesn't gunk up over time. I haven't noticed any critical spots, though, so I'm quite sure it will work nicely without cleaning for quite some time.
The main reason I love this grinder is → the grind. First of all, it's really quick; drier buds will need half a turn to one full turn for a medium grind, most other consistencies will be shredded with two to three full turns. The coolest thing though is the grind consistency: no matter what kind of bud I put in there, it always comes out superfluffy and extremely even. I must admit my experiences with high end grinders are limited, but when I see the grind results from grinders being reviewed on YouTube I almost always think that they are not quite as even as what I can do with the Gleichdick.
I've been using this grinder for about two years now, it definitely stood the test of time and works as nicely as on day one. I highly recommend it.
I don't know of any u.s. or international retailer, but they ship worldwide. Custom engravings are available too.
http://gleichdick.at