I'm Actually Playing Through The Witcher Now...
And it kicks large quantities of ass, in my opinion. I'm getting toward the end of act 2 (out of 5), and I've put a lot of hours into it. They aren't lying when they promise 60-80 hours of gameplay.
Not allowing you to pick class/race like many RPGs allowed them to focus the story a lot more, and it's a good thing. There's a fair number of plot points and characters to keep track of, and still a decent degree of character customization possible as you progress.
Good stuff: Decisions that make more difference than usual in an RPG. Tons of side quests that you can do or not. Challenging enemies and gameplay (I'm playing on normal difficulty). A real feeling of depth and history to the world. Fun dialogue at times. Being told "Your mother sucks dwarf cock!" Getting laid. BOOBS!
Bad stuff: Somewhat fussy and unintuitive alchemy system, occasionally silly/repetitive dialogue trees and canned responses, sort of lame drinking game, minor bugs at times, drastically cut dialogue for English version.
One of the best games I've played in quite a while. I recommend it.
Also, check the first post in this thread on the Something Awful forums for additional information and some good addons/downloads for expanded English subtitles and a number of other things:
http://forums.somethingawful.com/showthread.php?threadid=2718714