OK ... Haven't got the expansion yet because Paypal is dragging it's feet with my top up - there also might be an issue with my name; one part of my name appears twice for some reason which might gum up the transfer.
So far the new graphical features ...
Parallax Occlusion -
Too many artifacts. Rocks in particular due to their weird angles can cause a "ripple" predator camo effect.
Tessellation -
As mentioned early,
Both hit the framerate pretty hard on my mid-end rig. The effects aren't that big. The trade offs are too steep.
The only addition I have turned on is HBAO+(Standard) - HBAO+(High Quality) is ridiculously expensive. It's more expensive than SSAO(Strong) but the image quality is much better - also there is less flicking and false positives (dark halo around some objects).