Do you know the reason for tongue piercing? Besides cosmetic reasons. It's for adult pleasure (I'll leave it at that).
One person I knew that had it done had his tongue swell up so big he couldn't eat or talk.
Another person (my very good friend) ruined her teeth with it because she was always messing around with it and clicking it on her teeth. She had to have major work done to her teeth to fix it.
It can be distracting while you talk, but I've talked to people who have them and I hardly notice. I guess it depends on the size of jewlery you wear.
However, it is your mouth and your tongue. So you do what you want.