Back in the 60's I would have given my eye teeth for one of these beasts. I was able to handle one at a photo equipment exhibition and was smitten. But oh the weight! They was probably heavier than my Nikon F4's.
The non instant return mirror made the use very slow and deliberate act which would suit my photography today but in my youth as we all did we wanted SPEED!
Then about 2 months ago I had the chance to handle one again. It was in exquisite condition almost unmarked with a case that could have been unwrapped only yesterday. There was the same silky smoothness that was there all those years ago, the original Zeiss Planar F2 lens was attached and was as smooth to focus as any I have ever used. The meter still worked, although bit slow to respond. The price was reasonable too, so I pondered and thought about it, but eventually decided to give it a miss, a decision I will regret for a good while.
I am quite sure that all today's electronic wonders will never last a fraction of the time. They just lack craftsmanship and sheer build quality.