I've had a 3.5inch limpy for like 6 or more months now and it's holding up great. It stretched out to like 5 inches now though I guess just because it's hanging there. I like it, it suits it's purpose of packing well, but I'm ready for a pack and play now. Totally recommend it for packing though.
You can get it from early2bed for $12+$6.50 priority shipping.