Lami, I'd say give it a go if you're a fan of the series. The game has been quite entertaining up until now for me.
That "bitch" can be controlled via voice actions which bring her to you. However, you do have to shepherd her round like a sheepdog at times. If anything she's useful as an extension of your inventory and sometimes is quite helpful in tight spots. She does seem to waste a lot of ammo though, at times taking 5 or 6 shots to take down one guy when an easy headshot would have sufficed. Also, sometimes you need to double team up to open certain doors etc and it can be hard getting her to do exactly what you want her to do.
So far this game is a 6/10 for me. The graphics and cutscenes are sublime, however the control scheme lets it down for me. It's very clunky and at times very frustrating e.g. your character freezes whilst reloading and you can't move/strafe whilst aiming. The pistol also seems to be more effective than the other supposedly more powerful guns, the machine gun seems to be shooting rubber bullets and the shotgun seems to stun enemies rather than take them out in one shot. The game seems to have lost it's atmosphere too, it's more of an action game than a horror game for me.
Why do the zombies keep saying Kool Aid aswell? LOL
EDIT: Dead Space and Bioshock are definitely worth playing/trading for this.