I'm posting this to kick some life into this forum for 2007!
I can remember when the original Contax RTS was released. I read an article about it in the American magazine Modern Photography, and there was an ad for it that made it look incredibly desirable. I wrote to Photax UK, who were then the importers of Yashica, for more information. They said they had no details as the camera was so new, but would send me something when available.
True to their word, a few weeks later I received two glossy brochures - one on the Contax RTS itself, the other on Carl Zeiss lenses for the system. The lens brochure addressed the issue of whether resolution or contrast was more important - it was the view of Zeiss than contrast is more important. As I recall, they showed two extreme enlargements from negatives taken with both a Zeiss lens and a non-Zeiss lens. The grain was clearer and sharper on the non-Zeiss lens, which had really high resolution. However, when you looked at both photographs at 'normal' size, the Zeiss one looked better - more contrast and, as a result, sharper overall!
A few weeks after this, I took out a loan for £500 to buy and RTS with 50/f1.4 lens. I wish I had kept it ... I also wish I'd have kept the brochures!