We had a couple of cars that were magnets - including the Mini Cooper S on which we replaced the windshield 2x that's after multiple fixes some that worked, some that didn't.
We also had repairs done to the Baja, Impreza, Grand Cherokee, and Juke...all because the insurance co paid for them completely. All those repairs (some now 4-5 years old on cars we still own) worked perfectly, though the crack is forever visible (albeit reduced somewhat visually).
I think there were some repairs that I thought to myself "did the resin penetrate completely" but I don't remember any one of them specifically failing.
Lastly, the lifetime before that, when I was too poor to have insurance that would fix them for free I repaired a number myself using those kits at the auto parts store - the little suction cup and syringe... I remember having success with all but one of them (but luckily I had a brother in law who was a glass man at the time and got me a discounted windshield for the beater Chevy truck in question, and installed it with me on a sunny afternoon.