I am still playing, but my personal opinion so far is that anybody with an interest in story-driven RPGs should by all means give the Witcher 2 a try. It's got atmosphere in spades, its challenging, it takes its players seriouosly, it provides some really different choices and it doesn't shy away from presenting you with the consequences.
I personally really like the combat system and the difficulty level, but it is clear that it is a bit of a love-or-hate thing. Its more action-oriented and more demanding regarding positioning, evading, and use of the signs, bombs etc. - at least at the beginning - apparently later on the difficulty gets reduced. I die a lot, but I always find a different approach after a few tries that works - I like it, if combat is like that.
However, for someone who (I think) is mainly looking for deep character systems, elaborate character customization opportunities, and likes tactical combat - maybe its not for you.