More compact quest storage. I suspect that a GQ quest will be noticeably smaller than an identical KQ level, even given the greater limits of the GQ quest format. The quest author would determine the rate of HP and SP recovery. Dropped items can be found and picked up again. The quest author could prevent this from happening.
Monsters can have multiple attacks, with biases towards certain attacks.
The quest author could even create a monster that has a one-use spell, and always runs as soon as it has used its spell. I want to make sure that the events are flexible enough to do some interesting mechanics, like making backpacks. Part of a quest can be exported then reimported into another quest, to allow for modules. A backpack would be an example of such a module. The module would contain the item and all events responsible for moving other items into and out of the backpack.