I have used tents with floors and without. I see advantages in no floor. I use a light plastic paint tarp (as light as half mil) and secure the corners with rocks. I then wrap the floor up the sides of the tent a bit to keep out insects and water. So why do you need the extra weight of an untreated floor? The only advantage of a sewn in floor, as I see it, is when it is bathtub like and keeps out water that way.