I use one all the time. If I'm hammocking, I use a 3/4 length CCF pad inside, and that becomes my pad at breaks. If I'm tenting, I carry a separate piece of CCF as a sit pad. Just cut from an old Z-rest, and just large enough for my sitting area. Seems silly, but I won't hike without it.
It's multi-use, too -- at night, put it inside your sleeping bag under your feet for a surprising amount of extra warmth.