Ones made between about 1950 or so and before the modern ones with plastic parts for the burr set carrier are pretty good. Very even grind, durable, and look good. Before that date, they had some fiddly adjustment mechanisms, and the bearings were not sufficiently robust to stand the test of long use. Once the plastic bits came into vogue, they again lost what they had gained in the redesign of about 1950 or so. Typically the ones with the adjustment screw/handnut at the bottom of the main shart are strong and robust. When the adjustment is at the top above the bean hopper, the shaft and other bearings are too weak, and don't hold up. Some of the models made during the 1960's and 70's are astoundinly beautiful, I have some. Their "wahlemüllen" are definitely works of high art yet functional. The artwork on the ceramic bowls is amazing.
Their Turkish mills (nickel or brass cylinder shaped models) during the entire time they made them are very fine instruments, and can actually grind for espresso and turkish coffee. Their rival at that time and for those mills was the Peter Dienes company, building both in Germany and Holland. Pe De is an abbreviated name style for them, seen on many of their mills. I've not seen a DeVe "turkish" mill, but that's not proof they don't exist. I do have a number of the Zasso and PeDe turkish mills, though, some I think dating from the 1920's and 30's.
Finding any of these at the present time would be quite the challenge, though.... I've not seen one on eBay for years, and before that they were rather dear. I managed to find some bargains in Germany, France, and Holland, and took advantage of those offers.I think most of those have been claimed by collectors and such. Rather an esoteric branch of the industry, but for decades nearly every home in Europe had, and used daily, these hand cranked mills... box mills, (table top), knee mills (put between your knees to operate), Turkish mills, and the amazingly beautiful and artictic Wall Mills..... Trosser were the low price "chevy" range, yet even those were fairly high quality and withstood the test of time. Their burrs were not quite so well cut, thus not as clean, but for the average householder brewing in a French Press, they worked well. They are still worthy of note. The French Peugeots (yes, the car and bicycle company, coffee mills is how the "Peugeot Freres" started in business about 1885. Any of theirs, even the cheap stamped tin box mills, are worth getting if you can find them. All of them work well. I laughed out loud when I first noticed the short, stright bicycle spoke and nipples used at the four corners to hold the metal body onto the woden top and bottom!! Hilarious, and ingenious!! It works, is cheap, fixable, what else is needed? Those are fine mills. Zassenhaus are the better known here in the US< simply because they kept producing until well after all the other companies had folded or gone out of that line of product.