It's great. I'm not going to over hype it, but I definitely appreciated the fact that I could walk around a huge derelict city, and find interesting side content to do both outside and inside buildings. Then there's the story missions, lite-base building (like in the trailer), Dark Zone etc. Expecting good things based on what I've played.
There world is seamless. It's not a case of having your hub then warping to specific locations like in Destiny. You have a base camp but then from there you explore the city freely, no loading either.
Similarly with match making, you have to wait for your team mates to spawn in but I don't remember a loading screen.