Every bit as good as any GTA.
The overall game mechanics are excellent. Control is much better than any GTA game. Shooting things becomes a joy, not a pain as it is in GTA. The only suggestion I would make is when driving in cars, you always have to reorient you're view with the right stick. An option to have this done automatically would have been nice. I also think a first-person viewpoint while on foot would have been nice. Overall, though, camer angles are excellent for a third-person game and never an issue.
Besides all the afore-mentioned issues, gameplay tends to become repetitive and I wish there were even more things to do and places to explore. Other than all this, this game is excellent and I look forward to sequels.