I had braces as an adult and afterwoods I had horrible stains. I got talked into Zoom by my dentist, it was the best thing I've ever done for my mouth (besides braces). My smile is so much whiter. It's been 9 months and it is still so much whiter than my teeth were even before braces.
I did have some discomfort during the procedure, at some point it was a bit unbearable. But I have very sensitive teeth. 45 minutes of discomfort for (so far) 9 months of a beautiful white smile! I still drink coffee and red wine.
RECOMMENDATION: DO NOT DRINK COFFEE OR RED WINE 72 HOURS AFTER TREATMENT... The longer you wait, the better off you are.