Greenwise marmoleum is better then vinyl but I liked the concrete look of the Vinyl better. Besides this material is less sturdy and should therefore be easier to install.
The Forbo technical department gave instructions on how to do this in an RV. First we need a paper model of the floor. Remove all staples and other imperfections. Reflex paper is placed under the heat mats we purchased. Every dent or hole will be seen threw the Vinyl eventually so a layer of 3mm plywood will even the floor out. This is how far we have come.
This is how the floor looks today, yes its almost done.