Optically, it's not the sharpest lens you can find in this focal length, and wide open it's a bit soft and vignettes, as you can see in the first picture. There is a unique quality to this, and some other Meyer lenses. At wider apertures, the image exhibits a blend of sharp and soft quality, which in some pictures, looks really nice. In actual use, this lens, without a tripod, is very difficult. When I used it with my 1Ds or 1D II, it was much easier because I had a cross-split screen installed, but on the 5D II, which as a stock focusing screen, it's hard to tell in focus, or slightly off. Live-in is pretty useless in strong light. Another negative, is that the closest focusing distance is 6 meters (20 ft), so close-ups are out of the question.
So, it's a pretty inexpensive 400mm lens, which has good enough image quality for causal use. If you are a sharpness freak, the Canon EF 400mm f5.6 is your best option, if you shoot Canon, but what fun is that when the camera/lens does everything for you? Besides, there is practically no characters to speak of from images captured with modern lenses. They all look very similar, but not some decades old manual focus lenses :)
Weather Station - Meyer-Optik Telemegor 400mm f5.5. Click for larger.
Bird Dance - Meyer-Optik Telemegor 400mm f5.5. Click for larger.
Love Talk - Meyer-Optik Telemegor 400mm f5.5. Click for larger.
Tree - Meyer-Optik Telemegor 400mm f5.5. Click for larger.
The Giant and the Midget. On the right is a Pentacon 50mm f1.8.