I wasn't really aware of most YA when I was the target audience.

I think EE is the better book of the two.

The thing with Meryl was meant to show that she was thinking too small. Addie was thinking only of saving Meryl, but failed in that. In doing so, though, she saved thousands of other lives. It also made her be able to let go of Meryl, so Meryl could finally live her own life, instead of being ruled by Addie's needs. Levine seems to be pretty big on having her heroines learn life's lessons via a figurative punch in the gut.