I did like the Witcher 2 and in many ways the 2nd game offered a really good experience, especially in terms of story telling and atmosphere.
Compared to the first game however, Witcher 2 falls flat in a few area's.
I personally was disappointed with the simplified alchemy system of Witcher 2. Also the minigames (especially dice poker) were less fun than they were in the first one. Combat felt frustrating. Even though I eventually learned to work with it, I never enjoyed it in the same way as I did in the first game, mostly because I never felt fully in control of what Geralt was doing.