I install hundreds of 2 1/4 trim head screws and I find Panasonic to have the best power/ weight ratio and the best trigger feel. I have been using Panasonic cordless for about 12 years. I had three NiMH drill drivers and a hammer drill ( all 15.6 volt). Last year I got the lithium 14.4 drill I love it. Much lighter than the NiMh and the same 390 inch lbs of torque By the way, I have never gone to impact drivers for a reason only fellow tool geeks could appreciate I don't like how noisy they are! I work only inside homes, usually occupied and very high end, so I like to keep the noise to a minimum. For the same reason I use an air tank system instead of a noisy compressor for pneumatic nailers/pinners