I remember playing the first The Witcher up to the end of the first village, at which point the game crashed (a frequent occurence), I put it down, and never picked it up again. The gameplay was tedious and repetitive, the voice acting was flat and the characters were uninteresting.
But the real 300 point gorilla in the room was the 'mature content.' The Witcher was the first and only game where I've ever felt the need to play it exclusively with headphones so as not to irritate friends and family. Every villager and passerby feels the need to bombard you with random vulgarity, and the plot could have done without making everyone you meet a racist, murderer or rapist. I get that this is supposed to be 'dark' and 'mature', but it all just felt like gratuitous window dressing, not something meaningful or integral to the plot. If you stripped it all out you might as well be playing a Fable game crossed with an Excel spreadsheet. The whole experience struck me as inherently juvenile, and in a game that's trying to be taken seriously, this can become offensive real fast.
For instance, at one point Geralt was given the option of a)Saving someone from imminent torture and death, b)Abandoning someone to imminent torture and death or c)Saving someone from imminent torture and death if he could first 'get to know her better.' I'm all for having choices in an RPG, but The Witcher went so far as to give you the option of using the threat of death to coerce someone into sex. That just creeped me out, like all the people who complained that you couldn't kill children in Fallout 3.
So I have no real urge to play The Witcher 2, mostly for the fact that I don't care to know what happens to Geralt next. He struck me as the slimiest and most unlikeable protagonist in any game I'd ever played.