I have used Mantis and "regular" stereo microscopes. In my lab I have a regular type now. It is just fine, but I don't do soldering work that much anymore. I used to work with a Mantis. I tried USB, but there is no way I could give up stereo vision once I got used to it.
Mantis is superb in ergonomics, because you don't need to hold your head steady. You don't develop more neck ache than you do from computer work. With a regular microscope, you need to hold your eyes right at the eyepieces, which gives you a stiff neck if you do that many hours a day.
And of course, the optical view quality of Mantis is great, too.