F3
The UI and map system does need a lot of work, I found people tend to hang out in the city area but then you kinda lose the benefits of the open world. The "real tasks" aren't as much fun as crazy dynamic stuff that can happen randomly. (Sorta like the single player

)
Got into a random battle after grabbing a chopper with some guys flying around in jets. Meanwhile, these guys were grappling onto the chopper and trying to jump off and grab onto the jets when they made passes.