After being bested by a few stubborn nuts last weekend, I've decided on pull the trigger on a 1/2" impact wrench. Milwaukee makes a few that I like, but I'm trying to decide whether to go with an 18V cordless or just a corded one - I really don't see myself using it beyond the reach of a 100' extension cord from my garage, so I don't have to have the portability. But, the corded one I saw (http://www.smallparts.com/milwaukee...p/B0000647G9/ref=sr_1_3?sr=1-3&qid=1306090255) is limited to 300 ft/lbs of tq while the cordless is rated for 450. I'm an impact newbie - for you guys that have guns in this range, am I going to miss that extra 150 ft/lbs for stuff I'll typically run into? The price differential is $300+ between them. Thanks in advance!