I am a floor sleeper and did my fair share of research into the shikibuton, maintenance, comfort, materials etc...I have been looking for a Twind XL mattress...I finally decided to go with a combination of tradtional shikibuton and futon because I did not want to fold the mattress everyday. These all cotton, no spring mattresses are great for someone who enjoys sleeping on the floor or other hard and flat surfaces. You can fold it to put it aside or because it is futon or leave it on a platform such as a 2" boxspring which is how I currently use it on a daybed. Be prepared to have to flip it eventually and/or fluff it up. It's a good thickness, approx 4 1/2" thick so that you do not need two stacked as with some shikibutons that are too thin. Although my daybed is a twin XL and this mattress is only available as a Twin, it is still fit well on the thin boxspring I have under it and within the frame of the daybed and cover it with a cover. You can also use a bed sheet on it.
One downside is the smell. If you do not like the smell of cotton, you may not want the cotton version of this futon as it took almost one month of placing outdoors to air it out. It is much better now. I have had it for only one week so my opinion may change in a month or more but for now, I find it very comfortable and look forward to it feeling even more dense as I quite enjoy firmer surfaces.
Overall I am pleased with it for now!