The Yashica Electro is light years ahead of the Zorki in quality and technology. There are several variations of the Electro out there, but the only real differences between the G, GS, GT, GTN, and GSN are the flash shoes (and sometimes the film ISO range) otherwise they are about the same.
The Zorki is fully mechanical, which is good if you carry a light meter or can read the light well. Unfortunately for the Zorki, build quality is an issue. I have found with more than one Zorki or FED that shutter speeds can change noticeably by turning the camera sideways. The fact that you can interchange lenses is a definite plus, provided you use quality lenses.
The lens on the Yashica Electro is truly nice, and in my experience it is near the top of the hill among fixed-lens rangefinder cameras. You can find a working Yashica Electro pretty easily for less than the price of any Zorki, they are probably the best deal out there for a rangefinder camera. You should check out the images in the Yashica forum.