I got rolled into from some guy that forgot to hold the brakes down on his automatic car. It nudged my car forward slightly but the bumper popped right out with no problem. I don't have any experience with a real accident as I avoid those.
I never really worried about a real accident. As far as my understanding went, what is getting removed is the 5mph bumpers so the car could be damaged more in smaller accidents. Large accidents, however, would still incur typical damage. I don't know if this is completely true, though. The parts came from the factory on some of the STis so I figured if there were ok on an STi they were ok for me.
The beams held up fine. No sagging or misaligned parts. They looked factory (they are factory).