Stealth is a new option, although the game controls the opportunities: at certain scripted locations, you are given the choice to enter Stealth mode. While creeping around, Geralt can use a Sign to blow out torches and silent takedowns can be executed by successfully reaching an enemy from the rear without detection. I found one stealth sequence quite easy and, in another, I was repeatedly detected, so this might need more fine-tuning. Still, it's an interesting addition.
One potentially controversial aspect is the Quick Time Events. There are a variety of mini-games such as boxing, arm-wrestling, dice and more. For example, the boxing is reminiscent of Heavy Rain - you'll have to hit one of the WASD keys as a sequence flashes up. The choreographed animation is impressive but I'd prefer a direct control system. Arm-wrestling was dull and I didn't try dice. Most of these are optional but occasionally, they are part of a story sequences. For me, these aren't a successful addition but they also don't do much harm.
So, on to the most important aspect: how well are the choices and consequences implemented? I can only provide a limited view but I did observe a number of choices and optional approaches. Early in the Prelude a soldier asked for advice - during a pitched battle he added support and later explained my advice helped him survive that far. Flotsam has provided a raft of small choices and these build to a climax. You can choose to sabotage a weapon, using prostitutes to draw a guard away and later create a distraction with an arm-wrestle. There's an opportunity to sneak into a compound and collect information and one of the major encounters can be completed alone or with assistance - all of these have some impact later on.
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