I bought a new backpack last summer and a sleeping bag that requires an insulated sleeping pad. The pack was nice, but way over rated on the volume it holds, 90L and could barely get 35#'s of gear in it. I went cheap with the sleeping pad and got a lil cold at night in mid 30's weather with a 15 degree rated bag. I was warm except the area on the pad.

I took both of them back today, REI has a 1 year satisfaction warranty and they honored it today no questions asked. I got the full refund and put that toward a better pack and a higher "R" rated sleeping pad. This time I did some research and found http://www.outdoorgearlab.com/ to be be very helpful.
They dont just try shit out for a weekend, but actually take it out and run it through the paces and I went with one of the higher rated pads and packs.