My first run was in Update 5. A lot of things have been tweaked, but the major ones I think you’d immediately notice:
Hogs no longer circle. They might run a quarter of the way around you to take off in another direction, but no more spinny spinny. Pyroceratops now come in lots of colors. moar ammo! Same detonator, rebar gun and rifle, but there’s several ammo types for each with their own characteristics. Shock rebar, splinter rebar, homing bullets, etc. It doesn’t get as dark at night; it’s more like there’s bright daytime and blue daytime. Ceiling conveyor hangers exist. There’s a blueprint system now so you can build assemblies.