Was VERY skeptical before having procedure done due to comments I read here. Went through with it anyway. Had Zoom done @ 1:45 on Thur 15 Jan. Had no discomfort during procedure. Had maybe 15-20 "zingers" after. Last one was about 3 hours after procedure was completed. None since (18 hr later).
Teeth still feel a little bit sensitive, but nor pain, just feel weird. I have 2 front teeth that are slightly chipped, those are the ones that I had the "zingers" with. Teeth are about 3 shades whiter. Also received bleaching solution with what I paid for touch ups in the future. Will go back to have trays made up after I have some crowns and veneers put in. Needed teeth whitened before new crown and veneers.
I would recommend this to others if you never had any issues/sensitivity with your teeth. If you had/have sensitive teeth, I would not recommend procedure.