I knew a teenage girl with invisalign. She was about 15. I'm not an orthodontist but to me it DID look like she needed just a bit of cosmetic tweaking, so maybe for her invisalign was just as good. But frankly, listening to her try to talk with them in and how uncomfortable she obviously was from the discomfort of the aligners, plus the fact that I could see them, made me decide that option was off the table for me as an adult.
I worked at a large computer company 10 years ago when I had braces for the first time and I had zero questions or comments. You'd be surprised how little people actually care about that metal in your mouth. Maybe it's the fact that around here people have tattoos and gaged ear holes and piercings, but it's more likely that braces are just mundane now. Besides that, at my age I work with parents who have kids at the right age to get braces.
I'm actually worried I'm not going to get any reaction at all when I roll in to the office and give people a big shining smile.