Poncho liner is just about the most useful item of military gear you can have--roll it up tight and stick it in the pack, and if it gets cold in the box blind, take it out and cover up!!
And the newer models are not as packable/durable as these are. Best deal going for a quick layer of warmth, backpack hunters should be buying all of these.
Try and find a heavy duty Gore-tex sleeping bag cover for under $40 anywhere.
