Just what you'd expect
This product fits perfectly under the Aura to keep it clean and lengthen its life - It also allows you the versatility of setting the tent up with just the Fly and Footprint (barebones setup). The footprint comes with its own little stuff sack which fits nicely inside the main Aura stuffsack.
You'd save money and weight with just a scrap of Tyvek, which you could probably pick up free from a construction site - but you wouldn't be able to do the barebones pitch (it requires the footprint grommets). It is also kind of annoying that the stake tape used on this and the tent (slits cut in a piece of webbing) do not accomodate wider stakes like the MSR groundhog.