My fiance got them right before I met him about 6 years ago. He still says he regrets it.
I don't know what his teeth looked like before - he refuses to show me pictures. But I do know he got the veneers mainly to correct uneven staining and fillings, not crookedness. He has either all 6 or all 8 top front teeth done. Personally, I would have gone whiter if it was me, but his dentist made them only one shade lighter than his other teeth. Also, he measured wrong (which is insane because he went to this really expensive dentist who supposedly does this for celebrities) so one of his front teeth is a hair longer than the other. I never would have noticed on my own, but once he pointed it out, I could tell. The dentist offered to correct it for free but my fiance didn't want the guy to damage his teeth any further.
One of them has chipped. It is his left eye tooth and it isn't super noticeable, but it is there. He has not been able to afford to get it corrected, but aside from worrying about it, the chip has not caused any pain. I guess it chipped from age or something - or perhaps the veneer was not stabilized correctly - it is hard to know. My fiance does not bite into apples, sandwiches, bread, etc. anything moderately hard to hard because he worries about chipping his teeth. He has to cut everything up (which is such a pain because I'm a grab an apple and go hiking kind of girl).
Overall, his veneers have caused him a ton of insecurity, which is sad. I don't know what he was like about his teeth before I met him though, but he is totally neurotic about them now. He also claims the veneers changed how he speaks slightly, but he believes this is because the dentist measured them wrong. He is a lawyer and wants to get them corrected when we are more financially able because he worries about how he is speaking with his veneers when he is in the courtroom. So, that's everything I know about veneers. Really make sure the dentist you go to knows what they are doing. I don't think everyone has as bad of an experience as my fiance has had. He regrets getting his veneers, but I think if he had gone to someone else he'd be happier with the results.