The Witcher 2 has surely managed to gain a place among the best Modern RPGs!
Sound: As with Witcher 1, absolutely AMASING soundtrack (although to be honest i liked Witcher 1's soundtrack best), terrific voice-acting and almost perfect all-around sound effects.
Gameplay: Ok here is the tricky part. First of all forget Witcher 1. CDP Red has given us something new here. Gameplay can be really difficult and frustrating to the newcomers. But believe me once you get the hang of it, the battles will progress a lot more smoothly and with a lot of fun! Only negative i found in the game is it's poor "take you by the hand" tutorial. You MUST study a lot your Journal! Also be aware that the gameplay also includes mini-games through the campaign. (mini-games like: "something" is heading towards you in slow-motion (cutscene), hit left mouse-button repeatedly or die :) )
Story: A very interesting story-line with WAY too many alternative options throughout the game. I guess that's why the game has 16 different endings. Although the playthrough of one time is a bit short for an RPG, the game makes up for it's replayability to see other sides of the story and live the events of another option you could make.
Be aware though that the game isn't without bugs. You'll encouter plenty of them, the most annoying i had was with inventory items: i collected something from a loot or from a convertation (not quest item) and nothing appeared in my inventory. If you can't stand with bugs, then i suggest you wait a bit for CDP Red to fully patch the game, i believe it won't take more than a month or so.
Truth is i was VERY dissapointed by the sequels lately, (Dragon Age 2, Crysis 2, Mafia 2) i started to believe that the industries are truly just trying to get money from their successed titles by just making a crappy sequel which will carry the name of the successed one. Thankfully The Witcher 2 is here to prove me wrong.
It's worth your money, CDP Red is worth a bravo. Give it to them.
P.S. Another amasing step by CDP Red: If you buy the game from www.gog.com it comes without any DRM!