Ditto me, no issues. Our local running club is using them full time now.
Three races with them for me I think. My bib gets wrinkled and I wear it on my belt - no pins. I think they just tell us that because that is probably the preferred method. If it somehow messes up and you didn't wear it the "right" way they can say it's your fault
Think D tag is my favorite. It comes on the bib so there is no losing it and I don't have to stop and give it back at the finish. But these B tags are fine.
enjoy,
Duane