I don't know if I'd call the world more open. There is clearly more sections/loading points/doors stopping you from advancing until it loads the next area.
It does have better graphics (which ties into the "better girly parts") but that is to be expected because the technology has advanced. The voice-overs are more or less the same as the they were in the Enhanced Edition (original was dreadful but I never saw it so that's coming from other people).
I would have to disagree on being "more immersive," the story of the witchers drew you in from the start because they are unique (13th century biologically enhanced humans for the purpose of slaying monsters). In The Witcher 2, that intrigue is mostly lost because not much emphasis is placed on it. I find myself not being sucked in at all.
Janky Controls? As I recall, The Witcher was mostly mouse driven. Keyboard driven is preferable, I agree, but it is a mediocre implementation of it so I'm almost wishing it was still mouse driven. There is certainly a pretty major issue with targetting. Often, you put the mouse directly over an enemy and it doesn't highlight the target. What's worse, you can't hit anything that isn't highlighted. Combat becomes largely about trying to get the highlighting to work and then getting hit by everyone else. Combat was for sure the most memorable gameplay attribute of the first but it is its greatest hinderance in the second.
I do hope they patch in a Fable 3-like selection system where the movement keys select your next target rather than using the mouse to look at the next target. Doing so really increases the fluidity of combat. At the same time, I can't help but think this type of game should still be mouse driven. If it isn't, then they're using the wrong game engine. The Aurora engine simply isn't intended to be deployed in this fashion. They should be using Unreal or some other 1st/3rd person oriented engine.
I'll keep playing it but, at this point, I'm not impressed.