I purchased the three-quarter length version and have…
Price Paid: $59
I purchased the three-quarter length version and have never had a problem. I chose to have a wider and thicker pad to sacrifice the length. The only time you really need anything under your legs is in the winter and you can always shove your coat and extra clothing under your legs.
I recommend getting the Therm-A-Rest chair to go along with this. Great to relax in after a long day of hiking. Just make sure if you're sitting around a fire to move it away if you get up for a bit. I haven't found out what a spark will do to the pad and I don't want to. Even though I haven't had to repair it yet, the little a repair kit weighs is well worth bringing.