Finally got this last night, played for a few hours, and am definitely loving it, even though it's rough around the edges. The graphics are great and while no eye-popping "this is next gen" moments yet, the fidelity even at 900p and absolute perfect smoothness of the framerate keeping 30 and never dipping is clearly something that would have been impossible last gen (so for the popular comparison, it does look both better AND worse than GTAV on last gen consoles, but mostly better until you start focusing on details). Driving is weird, it's like a compromise between more "realistic" GTA and "overly-arcadey" Sleeping Dogs, which makes the cars handle manageably but pretty meh, but I actually love how the motorcycles handle (I would actually say WD has "perfect arcadey" motorcycle handling/physics) and it's a joy to just rip through the city on them. "Life" in the city is definitely a step up from most open world games, with the situations and conversations being a really nice touch over the standard random people walking and saying random things to the air, and the phone stats/phones/messages adding on to that, making it a nice step into open worlds feeling more alive/immersive. Also loving the random crimes/criminal strongholds/etc missions that seem to come up as I listen in/get alerts. I know the ones always on the map are single-time activities but I hope those random pop-up ones never stop even if they repeat. Hacking is fun though I wish there were more opportunities to do things beyond "hold square/wait to HAX" in the open world. I feel like this is the area that needs the most expansion, it's a game featuring hacking, I'd like more random activities related to it (like break into someone's secure system for data using a randomly generated hack-puzzle, and more hack puzzles if there aren't any beyond the flip-path thing, or having multiplayer hacking actually being more than just find enemy, press square, wait/attack (competitive intrusion? How about an attack/defend game where one side is actually setting traps/locking paths to keep the other guy out?).
Even though I've barely scratched the surface I feel like this might be this gen's Assassin's Creed 1, which is not an insult at all. It sets a template, has lots of potential, takes a bite into next gen ability but clearly a bit rushed in spots and rough around the edges. Great game now at the start of the gen, but I hope that after the inevitable Watch Dogs 2 we'll be saying "Wow, with all the improvements to hacking/driving/etc, it's hard to go back to WD1".