There is very little difference in loadablity and longevity. The only real issue is that STS hulls are made for Remington primers, which are more expensive an harder to get these days. Remington Primers have a dome shaped top. Remington hulls have a primer pocket shaped to fit the domed top. You can load STS hulls with non-Remington primers, but the first time you have to seat the primer into the pocket with enough force to displace the plastic. On subsequent loads non-Remington primers will go right in. Nothing dangerous but it is a pain to do sometimes.
If you have a local trap club, you can usually buy hulls for a lot less than ordering them online.
Michael
