I'm waiting for my Yashica Electro GSN in the mail any day now. I did a bunch of research and had similar needs for a rangefinder. The GSN really fits the bill. As for the mercury battery replacement, there is a good video on youtube - just search Yashica GSN battery replacement. I, too have heard they are 'big' for a rangefinder but so it goes. I'm not willing to pay for a Leica or Zeiss Ikon (yet!)