They are a great camera. The rangefinder design means that you don't have the mirror slap problem found in medium format SLR cameras and as a result will get great images when handheld.

6x7cm frame size means you can print big
Lenses are good
Camera is compact and cheaper than other options.

Build quality is not to the same level as Leica or even the big RB/RZ bodies and the rangefinder will probably need to be calibrated more often than with a Leica.

Go for it!