Leica's digital cameras are ok, but not as good as you might expect. I think you pay for the name and with the Digilux 2, the identical (developed jointly) Panasonic DMC-LC1 is several hundred pounds cheaper, and still overpriced for what you get. These cameras aren't rangefinders BTW - the only digital rangefinder currently in production is the Epson RD-1.
Here's a couple of sites with good examples of what you see through a rangefinder viewfinder...
http://licm.org.uk/livingImage/Rangefinder-Camera.html,
http://www.photozone.de/3Technology/camtec2.htm