Downgrade? They added a lot of wind particles and atmospherics. The beta footage looks much better and more lively because of that. Textures also seem more detailed and less repetitive. I see that they had one more tree in the early footage, but other than that, just about everything else looks worse or same in it.
In any case, I played it yesterday, the game is quite gorgeous and feels like a spiritual successor to Halo. Technically, it's not quite KZ:SF or I:SS, but the art direction is on par with those and unique enough that it amazes every so often. Also, I can feel this judder problem a bit, but it's not a big deal. Wish they would just offer an uncapped framerate option.