> I had one of the super light and compact sleeping pads develop a leak after literally about three days.

Therm-a-Rests are a dependable brand in this regard, as while a leak may happen from time to time (I have had two punctures in about one year of sleeping outdoors), it is usually very easy to find the hole and patch it yourself, just like you do with a bicycle inner tube. I think Therm-a-Rest even includes the patch kit with some of its models now.