I have the floor saver for the 6 person tent . It does ok on flat , grassy ground but on rough, rocky ground I noticed holes on any areas under stress. Such as where a cot was or door entrance. The floor saver needs to be a lot thicker to be of any real use as I have had to put another tarp underneath it to ensure that the floor does not get damaged. I had to return the tent once due to holes getting in the floor of the tent. I must say though that their customer service was excellent as they replaced the tent and the floor saver as well as through in tent floor liner.
Handy when setting up tent as helps give the lay out of tent before you set it up and shows you what area to clear logs and rocks. If was of heavier material would be very useful. Suspect will only be able to get a couple of trips out of it before too many holes.