Myya, an advertiser on this board, has a pierced tongue as well, and she gives a great bbbj.
Besides Myya, I saw an SP recently with a pierced tongue and her cbj was fantastic (I usually don't even bother with cbj but I was curious about bj skills).
About a year ago, I saw an SP with a pierced tongue that provided bbbjtcim and it was amazing, I saw her a few months later and she had stopped providing bbbj and her cbj was unremarkable even with the pierced tongue.
I think the SPs bj skill and technique contributes more towards whether or not the bj will be great, but in some cases, the pierced tongue will enhanced the bj experience.
