DoDMERB is like a woman's pregnancy and birth.
Some posters will have nightmare stories, some it will be a walk in the park. Like a pregnancy nobody enters expecting they will be aligning with the nightmare posters. Like a pregnancy, all you know is you will go through it, and you hope to be the walk in the park, but prepare yourself to be the nightmare. Like a pregnancy, don't listen too much to the nightmare stories. It is a case by case scenario.
One thing I strongly advise is to be aware that the exam is only the 1st hurdle. If the candidate/cadet gets injured even after qualifying, they must inform the branch.
DS had no DQ's when he went as a sr. in hs. However, knowing that 4 yrs later he would have another exam, this time for commissioning any injury that may occur during those yrs were going to be addressed immediately. If they think they may have injured their foot playing ultimate frisbee, have it checked out for safety sake. It is not the time to play arm chair doctor. Don't confuse this with going to the doc for a limp, but if it was still a problem a few days later he went. PT and running on a hairline fracture can become a bigger issue than you want to deal with.