Just to share an experience. I went with an ID(Design Practice/Polaris) that had a portfolio of screed floors only to get it done badly. Just read the Nov 2012 issue of Home and Decor and they say it costs $2psf (mine cost more than twice that amount!) The article continues by saying that since it stains easily they actually lay plywood protection. My ID just loosely covered it with a layer of plastic and a layer of cardboard which of course tore holes though the renovation process and left many stains. Worse there were footprints and other stains and imprints left after the renovation. It was my dream to have beautiful screed flooring. Turned out to be a nightmare!