ZiggyD posted a pretty fair video after 20 hours of beta.
https://www.youtube.com/watch?v=FLOpHNoudM4 I've watched a fair bit of him playing in coop, there are some good bits in there along with a lot of issues. When you strip everything else away, you can explore a Fallout world and play Fallout quests together with your mates. That alone is going to make it worth it for some people. The locations I've seen are often good looking and the world seems to be very large.
On the bad side, it's an extremely shoddy PC port, there are numerous bugs apparent already (I saw a couple different quests break, and multiple issues getting people into the same instance, friended and partied up.) The fact that so much seems to be client side strikes me as a catastrophic lack of game security - I have no idea how they are going to stay on top of cheating.
Lastly, despite the measures taken the gameplay does seem to be susceptible to PvP griefing. If you build a couple base buildings for an income, then a couple of stronger players arrive, what are you going to do? They can steal the items your machines are making and become wanted, but if you engage them they will kick your ass. And you respawn 50 metres away so the situation remains. As far as I can see, other players can still disrupt whatever you have going on in the world, and if they are too strong it seems you have to move on elsewhere and hope they don't follow you.
So if you are pretty lucky/successful at avoiding the issues, there is some fun in there to be had, but I still feel like this game has a lot of problems and is overpriced for what it offers.