Classic camera author Ivor Mantanle says of the Contax rangefinder that regular use of the camera will keep the shutter running smoothly. I tend to agree with that statement.
Generally, the post-war Contax is a simple camera to service - despite what others might say. The design is a solid one, from a mechanical standpoint.
Personally, I think the meter of the IIIA adds a noticeable amount of weight, and I'd rather use a IIA and a handheld meter.