It's purely durability, especially with the flat end. The Intertronics version seems like a fibrous plastic like those big black shipping containers, and you can't snap them in half without a significant effort. This helps the flat end especially (and the pointy tip too) retain its original shape for far longer than a lot of other black sticks. The ones in my possession now are ones I've had for years. This hasn't been the case with other black sticks. And, even though they offer superior durability, they don't seem to be any more damaging to plastic surfaces. You can still use them to pry open all kinds of things and not worry that they'll damage the surfaces. Now, I guess it's obvious that I may not be using them for their intended soldering purposes, so there's that. But, we always found black sticks in general to be one of our most invaluable tools. Prying, directing cables, pushing down on tiny connectors... these are just some of the uses we found for them and we'd sometimes spend our entire quarterly parts/supplies budget on just black sticks. Mac Geniuses would horde and hide their personal supplies of the Intertronics version. This may have been why we had to keep ordering them ;)
