The Gun play is addictive and sadisfing but if you were excited by the open-world, it's lacking. Not lacking as in not a lot of activities to do, but how repetitive they are.
The road map lays out a few interesting updates but not really sure I'm going to be playing all that much after the story.
I do not know if there is a fun end game to this open-world shooter. From what I see, it's more of the same repeated activities.