Some GA collectors don't like strip reprint books, but the serial strips from the newspapers tended to be better written than most of the stories written strictly for comic books. To get a newspaper serial, an artist/writer had to be the crème de la crème.
With some notable exceptions, like ECs, GA stories were mediocre. They were primarily written for children and teenagers, so most of them would not hold an adult's interest for very long. I do occasionally read GA comics just for fun, but most of the time I'm having a chuckle at how wacky some of them were.
I haven't read too many recent comics, but the ones that I've checked out haven't held my interest much, either. The best stories I remember reading in comics were some of the Batman story arcs in the early 70s. I haven't found any GA superhero stories that are on par with those.
What do you mean by adult-type fare? Are you talking about material for teens and very young adults? I'm sure some pre-code books targeted comic book readers who had outgrown superheroes, but I have a hard time envisioning many 30- or 40-year-olds reading comic books back in the early 50s. I would think that children and teenagers were still the target audience for most of the material that was being published.