So having "finished" the beta, here are my impressions... It's ok. But if you compare to other open world games such as the latest GTA, Saints Row, Red Dead Redemption, or Just Cause, it lacks any actual story or character. The weapons are all serviceable and get the job done. But when your opponents are all brain-dead AI (it still fails the "pile of bodies in the doorway" test), the minor weapons differences aren't important enough to make a difference.
If you want to just play this game solo, I'd say it's not worth it. The other 4 I listed are better and more memorable. So the only thing this game has going for it is the 4 player co-op. Haven't spent a lot of time in co-op yet so I'll save judgement. But I'm tempted to say it'll be like the Division co-op. Except there's no PvP and you're exploring a much larger area that's also less dense (Urban vs rural countryside). Now that I think of it, this game is exactly the same as the Division except no PvP, no loot grinding, and you have vehicles and some AI companions. If that sounds good to you, then maybe this is your game.
So I'm a little underwhelmed. It still has all the fun "get every upgrade on the map" feeling that feeds my compulsion, but I've done all this before in more interesting environments. Maybe the final game will have a lot more. I get the impression that they've only shown a tiny portion of the overall map in the beta. I like the idea of playing with 3 other buddies, but I can usually get the job done myself with just a high perch and a sniper rifle. If they make it so you HAVE to work with other people, then the experience might become more memorable. But that would make the game less accessible overall. I dunno, this game doesn't feel like it's different enough to recommend at the moment. Maybe the final product will reveal more.
What's everyone else's impression been so far?