Since it's awake and I don't recall seeing it the first time around, I am going to put my two cents in. I have the Milwaukee M4. It's fine if you have patience because it is sloooow. Mine is in the basement and gets used twice a year to take the access plates off when it's time to tighten up the wall anchors. I also have two Makita 7.2 volt impacting stick drivers, one is the original style and is on it's last leg. It took some time to get used to since it's not a variable speed and runs rpm with no load, but the torque is low enough that it doesn't have the guts to strip anything out or do any damage it's now in the garage, but I bought it before I was married 14 years ago and used it almost daily up until it got replaced last summer. It has installed thousands upon thousand of screw whether it be electrical devices, light fixtures, or ceiling fans, that's what I used.. The new style is even better, the switch is improved and can be used from both sides, and it's now variable speed. I think the speed is even faster, but that's with no load on it. I'm not sure about the torque, if it's a little more it's not noticeable. All of them can be used straight or pistol style, but I don't think I have ever used any of them straight, it seems very awkward.
You will get efficient and thoughtful service from ehimax.
If you want to learn more, please visit our website Torque Electric Screwdriver.