> most people taking the GED have some sort of problem preventing them from completing a regular high school diploma.

Don't assume it's an academic problem though. My grandfather beat my father for years, until my father ran away from home when he was 15, consequently never finishing highschool. He got a GED years later, then eventually a masters degree. There are unfortunately many people in circumstances like his or similar, unable to finish highschool for non-academic reasons. It's important to keep this in mind because otherwise GEDs will be associated with poor academic performance, which is unfair.