Most of this was also present in The Witcher 1, however, albeit in a somewhat shallower and less detailed sense. What the second installment brings here is what makes the huge difference: playability. Graphics are now incredible and lush, the UI is beautiful and well designed, the fighting is varied and exciting, and the writing is excellent. None of these were present in The Witcher 1.
However, there is the nagging problem of the difficulty curve. The game starts out extremely hard, forcing you to lay traps, use bombs and spells, dodge attacks and position your sword swings correctly. But as you level up, this gets gradually easier and easier until you reach the level where using a few spells and being smart with your swordplay is usually enough. It makes you feel more and more powerful, but it doesn't match the constantly upping-of-the-scales in the storyline which should have made for more difficult battles. It's not a huge deal, but it's poor design.
Then comes the biggest problem with the game: the boss fights. There are two, and they are both completely and utter trash. They make sense in the story, but they are essentially just an enemy that is MASSIVELY harder to kill and to fight than anything else in the game - I tried all I could and used every technique in the book, but eventually I bumped down to easy, as I could not even get halfway across their health bar before dying. The game simply doesn't prepare you for this at all, and the incredible frustration hurt my enjoyment of the game.
An imperfect masterpiece, then, but a must-play.