Need a cordless impact wrench... Suggestions, please

Before I ordered the DeWalt (will come in this weekend) I read some reviews of several brands that could generate over 1,000 lbs of tightening torque. DeWalt was only 700. (Loosening torque was similar for all.) But my air-powered Chicago Pneumatic and 5hp single stage air compressor is lucky to hit 150 lbs tightening torque. And more than once, I've had to use a breaker bar to loosen something my air impact wrench won't budge. So I figure 700 lbs to tighten and 1,000 lbs to remove is way more than I will need.