I like you use the Kodak Retinas for rangefinders (Yashicas too). If you ever get the chance try the Retina IIIS and obtain the Schneider 28mm lens. Very sharp and the camera has an extremely quiet shutter. Condition of the camera, of course, will be an issue but with some patience it is worth obtaining.

I also love slrs and will always hold on to my Pentax equipment, but I do find that I have been using rangefinders more often.

http://www.cameraquest.com/ret3s.htm