Someone gave me one of these Retina cameras a couple of years ago and it is a sweetly designed and desirable little camera (although mine is the sort without rangefinder unfortunately.) Never the less I should get the darned thing out and actually use it, as photos I have seen taken with this camera / lens are very nice. I also have a nice little Voightlander Vito also without rangefinder. Its Tessar (sorry "color skopar") lens is similarly good, if very simple - having only 4 elements. Unfortunately its shutter is now stuck and I have never been tempted to pay to have it serviced (thats all it needs) as the service would still be worth more than the blasted camera. Never the less I got some great shots from it when it was still OK. And BTW, if you think a Leica M is silent to shoot - you should try one of these little leaf shuttered beauties. They leave Leica in the shade in that department!
If you doubt my word about image quality, buy a copy of the book "Collecting and Using Classic Cameras" by Ivor Matanle and look at the photos he has taken with both of these cameras. This is a great book incidentally and is well worth owning for any rangefinder or classic camera fan as he has made a career of using them himself. (He still writes for the British Amateur Photographer" magazine on this topic.) And you will also find he has written a similarly titled book on claassic SLRs.