A silnylon tarp (such as the Equinox tarps sold by Campmor) will be lighter (for the size) and more versatile. I can't see any reason for buying one of those ultra-heavy tent footprints. Strictly a sales gimmick to lighten your wallet, IMHO!
_________________________
May your trails be crooked, winding, lonesome, dangerous, leading to the most amazing view--E. Abbey