I agree with Phat about the Exped weighing more than an underquilt. The underquilt will not be useful if the user "goes to ground" for some reason. The Exped will work very nicely if the user needs to use it on the ground or in a shelter for any reason.

Also, I have the impression that the poster who suggested the Exped (Kent?) is using items that he already has.

CamperMom