I'm into my third batch of 20,000 S&B Small Pistol primers and have yet to have one not go off. In my opinion, they're a good primer, and I'll keep buying them.
If it takes a couple strikes to get a primer to go off, it's a primer seating problem, not a primer problem. The primer must be seated to the bottom of the primer pocket so the anvil can be set into the primer pellet. It's the mashing of the pellet between the anvil and the firing pin indent that makes it go off. When a primer isn't seated properly, the first strike finishes the seating, and the second strike sets it off.
I aim for -.004" below flush for all my primer seating and I don't have primer issues.
Hope this helps.
Fred