I use the dedicated footprints for both a small Kelty and a larger Marmot. I much prefer them to the plastic I used on previous tents. They fold up smaller and attach to the tent so you can move the whole thing around to find that "just right" spot. They keep the bottom of the tent clean and provide a clean surface for repacking the tent. I can't think of a good reason to not use one if it is available for your tent.