There are three "pro" level battery screwdrivers.
Milwaulkee 2.4 V and Panasonic 2.4 V (Essentially the same unit)
Panasonic 3.6 V
DeWalt 7.2 V.
I've used all three. The Pana 3.6 is the best in my opinion. The forward-reverse switch is in the best position and it has all the power you need. Second choice, Pana or Mil. 2.4. Same ergonomics, just less power.
The DeWalt is just not as well designed. If I need more power than the 3.6 driver, I use my DeWalT 9.6 drive or for serious stuff (driving 1/4" x 1.5" lag bolts into PT pole, no pilot hole), I use a Makita 12V impact driver. It's amazing and light.
