What is the deal with these things? I know about the little teflon o-ring and warming it up to get it on the fitting but the dang things are always such crap shoot to get sealed. I've done several of these things and I always have to fuss around with it to get it sealed. What a POS. Why couldn't they simply use a nice standard JIC fitting good for many thousand PSI?

Anyone have any insight on these stupid fittings?