It probably depends on how you work; the Paramo is my second cloth, the first being a weighted sheet of material and about the same size. What makes the Paramo better for me is that you can fasten it round the rear of the camera, rather than just draping it, and this means that I get a reasonable light seal without having to hold it. There are cloths that are made as sleeves - you can wear them round your neck as a scarf and then pull one end over your head and attach it to the camera, meaning you're looking through a light proof tube. The Paramo can be clipped to work like this.
I find that I'm working fairly close to the ground glass, and I use a pair of strong reading glasses to let me compose. By strong, I mean the strongest I could find, so I can view from a very few inches. And can't see my own feet clearly with them on! I've got used to working this way. I think I'd find a six foot cloth rather overwhelming to use, unless I had a larger camera.
The biggest problem I face is the cloth collapsing into my field of view and a smaller area makes this less of a problem; so unless I found from trying someone else's larger cloth that it worked better, I wouldn't go larger. The answer to the collape is to apply tension; easier if the cloth is smaller and clipped together.