It sounds like H1Z1 will be
the survival sandbox game when it's done — depending on how The Division is going to play out combat wise, because a huge urban environment is a lot more appealing than the standard rural worlds/maps — It would seem that DayZ is just way too slow with basically everything and frankly imo the ArmA engine is poop for MMO worlds, Unity doesn't seem to be up for the task either judging by how Rust handles full servers. A good engine specifically built/tuned for MMO worlds seem to be the key

I think it is a little
sad though that the sort of 'originals' whom even are usually sorta Indie, just seems to not get it done right, and now the big established companies are going to swoop in with the 'grand' versions of these original ideas.
Alas, it's still nice that Indie developers are leading the way to new forms of gameplay.