i am sure a square format RF with wind-on crank would be the cat's pajamas ... 🙂
Not necessarily so, the coupled RF's are a lot bigger and heavier in most cases. The mechanical advance is a major breakage point in most of them. And for some strange reason, some of them have a worse viewfinder than the non-RF models. Of course, for $300-500, you ought to be able to get a real good one, while the non-RF models are usually under $100. That has a lot to do with the collectors (CRF cameras are rarer).
The grass is not always greener on the other side of the fence. On the other hand, I just had to have an Iskra, based upon the very nice photos from them here on RFF. While I love the images from it, I am more likely to grab a lighter smaller camera, usually the Hapo 66E.
The 66E has a uncoupled rangefinder and mechanical frame advance (about 90% functional), but I usually do not use the RF, just guestimating the distance in meters (I actually guess in yards).
I also have a Kodak Duo that is nice because I can slip the back of the folding viewfinder up under my glasses allowing me to see the edges well.
The point of all this, is that even if you get one of the super nice coupled rangefinder cameras, you may find that you still prefer the simpler camera.