> How is a Rolleicord Vb to live with? Hard to use?

I have a Cord Vb and a Flex 3,5F as well. I cannot say that one of these is easier or harder to use. The Flex has a crank and film advancing is some fractions of a second faster. The most important difference lies in the lens: The 5 lens Planar is wide open sharper in the corners in comparision to the 4 lens Tessar. At f/8 I don't see any difference.
The Vb has the bright finder groundglass which is very good. You have with that camara a piece of equipment which can service you the whole life.
You need an exposure meter, I guess you know that.