The best camera I know to hold still in low speeds. It is a real pleasure to use. Zeiss Ikon quality makes everything smooth and reliable. The sistem to load film is not that convenient but yet better than classic Leicas screw mount. Other point that is not that good, or I did not find the advantage, is that it locks at infinit and you need to actuate the lever over the telemeter window to loosen it. One mistery for the experts: how come that the small focus dial on top plate does not cover the telemeter window ? What happens with the other side when it sinks in the slit ?
Well I don't dare to go into technicalities. There are so many Contax fans out there. Have a look on the   Pacific Rim   The section Phographica is just great.
Another good option is Camera Quest

Advertising featuring an earlier model
That was in a german book copyrighted in 1931 but obviously published later.
Knipse Aber Richtig, von Wolf H.Döring DWB