I didn't read all 7 pages, but here is my 2 cents worth:
I had carpet in my old sewing room, but my new sewing room has a stained concrete floor.
Pins get caught in the carpet and you could find them with your foot! Office chairs roll too much on the concrete so I have to put down low-pile throw rugs in front of the machines. The concrete is nice and cool in the summer, but too cold in the winter. Carpet has to be vacuumed, the concrete can be swept or gone over with a dust mop. (This would also be true for vinyl or wood.)
I think, over all, I like the smooth floor better. The stained concrete looks very pretty and I think it's easier to keep clean. I live in a warm climate so the cold floor is only a problem for a couple of months. I just wear my shoes and socks.