Decent action game, terrible RPG.
Witcher 2 is an action game with weak RPG elements, pretty good Choice and Consequence, lame combat and a decent story.
The combat is entirely action game like, it relies purely on your timing skills and what little stats there are in the game barely affects anything. Combat is neither fun hack 'n' slash nor is it one bit requiring any strategical thinking, instead it's a lame mix between the two and it doesn't work at all.
The game world is so small in scale and so confined and linear I felt like playing call of duty, there is almost no exploring in this game and what little side quests this game has, happens in the exact same area as main quests, usually even has the same objectives.
Witcher 2 also tries to create an illusion of massive amount of items, but in reality all the stuff from monsters is usually near useless, I am not exxagerating when I say that I changed my weapons and armor once in the game and I didn't see reason nor abbundance of choice either.
So if I'd rate it as an RPG I'd give it 5/10. if I'd rate it as a "game" I'd give it 7,5 maybe 8.