if you know you want a footprint then you should buy this. it's reasonable quality and will fit your tent perfectly.
if you're not sure if you need a footprint then i reckon you can give it a miss. it just adds weight and cost. the base of the kelty salida 2 is already reasonably strong, and unless you plan on doing something silly like camping on sharp stones then i don't really see the point.
This review was written in the old system and had content requirements that are different than reviews written today.