After playing Bioware games, I can't really get into the story when I don't have "buddies" with me, with whom I can communicate, share feelings and insights etc. I tried Witcher (the first one) 3 times, but I was too alone in the world. If there wasn't Siegfried and Shani, I would have ended with it even sooner.
I really liked The Witcher. (I have only played part 1). Parties are good for turn based combat or real time with pause. Companions are worse in real time action games. some examples: - I play KotoR now and my main char does about 90% of the damage. Your companions are mostly there for story reasons. - In Fallout3 and skyrim, my companions ran away because they saw a rat (or something else) at the horizon and they chased after it and then they ran from one enemy to another. When I have a gun (or bow) I play as sniper (move slowly with stealth and aim for headshots from great distances) so companions are often more harmful than helpful.
my result: Companions are good when you have full control over them (in combat, RP or story is something different). I mean you can control all of them all the time. If you can control only one at a time, the AI is often so terrible that you feel they are addicted to committing suicide. (There are 20 enemies ahead and I am a fragile mage. Lets charge right in and when everyone surrounds and bashes me I trow a fireball at myself, so I hit everyone.)
Prof. Dr. Dr. Mad S. Tist
World leading expert of artificial stupidity. Because there are too many people who work on artificial intelligence already
Prof. Dr. Dr. Mad S. Tist 
