I would recommend 18v 3 speed impact driver as the speed adjustment allows for a huge range of flexibility. Even with variable speed trigger it is very easy to over drive a screw in softer woods. I would recommend the Milwaukee 2753 it is super compact and extremely powerful. Dewalt DCF887 is also a great impact driver with plenty of power and excellent ergonomics but I still would recommend the Milwaukee due to there overall better 18v lineup.