Awesome for camping or backpacking alike. I have had the same one for 11 years now and its still going strong like it was brand new. They are very durable and abrasion resistent. I have used mine in the winter as well as all other seasons. a Thermarest will keep you warmer in the cold than a regualar pad will as well. The figure that i have read is that it keeps you 10 degrees warmer than what your sleeping bag rating is with a nromal pad. After sleeping on the snow at 9,000 ft and -40 degrees F with mine I believe them.
Certainly a well made product and far superior to nothing, but it didn't get it done for me. For the same weight or less, you can have a blow up pad that is much more comfortable, thicker, bigger and warmer.