Update on the ALZO Copy Stand.
As mentioned above, the first ALZO Copy Stand I got from Amazon (USA) came out of the box with a broken gear track for the height adjustment. Amazon quickly resolved that problem with a replacement. They even had the broken one picked up from my front porch, so I didn't have to go to a UPS store to return it.
The gear track was fine on the replacement. When I asked ALZO about this problem, they said their Copy Stand has a one year warranty - and if a gear track gets broken, it is always in shipping, and not from normal use.
However, my replacement ALZO Copy Stand had a new problem. The tripod screw used to attach the camera to the mounting plate was not fitting correctly into the mounting plate. Customer service at ALZO were quick to reply to my email, and they sent a washer to install under the tripod bolt head. That would have been an OK solution IF the washer had been the perfect thickness - but it was not. By sanding down the washer on wet-or-dry sandpaper I was able to reduce the thickness of the washer enough to make it work. ALZO says this is not a common problem.
In my mind, it would have been far better if ALZO would have sent me a functional mounting plate assembly rather than only a washer. ALZO customer service did give me a partial refund of $20 for my trouble, so thanks to ALZO for that.
Out of the box, my mounted camera was not perfectly parallel to the copy stand base, but adjustment screws in the ALZO mounting plate allowed me to easily correct for the small amount of sag. The height adjustment knob works OK, but there is no mistaking the feel for a top-shelf precision instrument. I find it helps to give a helping hand when raising the camera. If you are copying only one size of film at a fixed magnification, you wont need to change the height after the initial setup.
In use, the ALZO copy stand is a definite improvement over my tripod setup with the central column inverted (a Bogen 3001, aka, Manfrotto). It's much quicker to set up the copy stand and get everything level. And it is sturdier, too. I notice it most when focusing. With the tripod, I had to take great care not to put any up or down pressure on the focusing knob of my bellows; otherwise, the image would change focus when I released the knob. No such problems with the ALZO copy stand.
So, the bottom line for me is, the ALZO Copy Stand does an OK job, about what you would expect for the money - assuming you get a good one. And if not, ALZO customer service will work with you to try to make it right.