Well i've had a bit of a play with it, not nearly as much as i'd like to (and i am talking about the game) because i'm so busy with work and family but i can say that It's quite impressive. It has a lot of new features, weapons, nice screen resolutions and ratios, a couple of the maps are the same as in the original but they look so much better, no longer do we see that ridiculous dark images. The graphics are noticeably sharper and crisp. The rest is hard to say as i only had a quick go. Looks like you have unlockable weapons too, as you gain experience, even in single player.
All that said this should have been done in the original game and Ubi should not have screwed us around.
Heres a few shots from my pc:
Here is a vid i made showing some R6V2 terrorist hunt and story mode action: