[YardPro]

I think that if you use 1/2 that amount of torque you will never get the blades off. I try not to really bare down with my $49.00 electric impact wrench. Even my dealer when installing blades just barely tightens them after the get to the knocking sound and thats a plenty. That Dewalt you are looking at will surely get the job done!

that's only 120 ft lbs.
you can do that by hand..

BUT that's plenty
also the blows will help loosten stuff easier than a steady run by hand