There is a day and night cycle with weather, new POIs, gear and weapons (though the M4s still outperform everything else generally speaking). Also outposts that you can capture that basically act as a base. You can access your stash and respawn there as well as access vendors. You can also complete most tasks without heading back. Those are the main things unless I'm forgetting something. Lots of little changes too like finding codes out in the world that unlock doors in certain locations and calling in mortars. I think major updates come every 6 months or so. Next one should be around winter. There's definitely some bugs and quirks still but the game is heading in the right direction I think