Comfy, even for a big person.
I'm a big fella (235#) and wasn't sure a sleeping pad could really work all that well, especially since my only prior experience with a pad was a cruddy foam one.
This thing is *amazing*. I've actually been using it at home, just laying it out on the floor, grabbing a sheet, and crashing. I wake up feeling better than I do sleeping in an actual bed.
I'd encourage the purchase of the Lounge Chair that Thermarest sells (http://www.backcountry.com/therm-a-rest-trekker-lounge-chair). It allows you to use the pad as a camp chair, which feels just awesome after a day's hike, and it also protects the pad from punctures and make it more comfortable when sleeping.