I have the 12v Milwaukie Impact driver, and I love it. Especially the fact that it has an adjustable clutch on it that many including my Makita don't have.
I kinda thought that way but when it comes to furniture and the smaller #7 pocket hole screws and regular square drive #8 going into hard wood you can very easily split the wood if you put a little too much on it. I still prefer the drill driver for applications where too much torque might screw things up. For rough application where appearance at the screw location is not a factor the impact sees a lot of action.