I've had a zorki - another Russian RF
They are great cameras, but not without thier faults ... Reliability is hit and miss as from what I understand quality control was dubious! If you get a good one, it's the cheapest way to get into interchangeable lens RF cameras and you will I'm sure enjoy it!
This is interesting Russian Leica Screw Mount Rangefinders
Hamish is right and Pete almost so. I have a FED 3 and a FED 5. I also have a Zorki C and a Kiev 4a. My Zorki and my FED 3 have shutter problems. My FED 5 has a light leak that puts a bright spot on the lower right corner of almost every frame. My Kiev works very nicely. (So did the two FEDs when I first got them.)