I'm in the middle of Act II right now. My thoughts:
1. It's a okay RPG. Kudos to not having the standard, "The fate of the universe lies in your hands" plot - I'm utterly sick of this. Although, who knows? Maybe the game will turn into that.
2. I didn't read the manual at all - I had no trouble figuring out the game, and I mostly play console games nowadays. I don't know what Yahtzee's issue is.
3. Act I is a really obnoxious introduction into the game - there's way too much running around the fields of that damn village for all the "go get it" quests. A more tightly-paced first act was needed.
4. The sex - meh. I agree with the others - make it more explicit or remove it entirely. As it currently stands, it's much too reminiscent of lame paper & pen RPG sex sessions, like those illustrated in the immortal "Summoner Geeks" video ( http://www.youtube.com/watch?v=zng5kRle4FA) - "Where are the cheetos? If there are any chicks here, I wanna do 'em!"
5. I also don't get what Yahtzee and other mean about "one click combat", when he first complains that the combat is too complicated. I'm playing on hard, and the combat is not trivial, but aren't all games pretty much "one click combat"? Half Life, loved by Yahtzee, certainly doesn't feature difficult combat, and he clearly hates the ultra-complex combat of fighting games, so what exactly is fun combat for him? The Witcher is an RPG; that means it's combat is going to be mostly stat-based, and not twitch based. By that standard, it succeeds. It's certainly far better than the sleep-inducing combat of beloved RPGs like Planescape Torment or Oblivion (both of which literally put me to sleep on several occasions while fighting).