An undersized extension cord will shorten the life of power tools. I recommend a good 12 gage cord in the shop.
The more amps the tool draws, and the longer the cord is, will determine how much heavier of gage wire is needed.
I have had good luck with my Dewalt, I suppose you could have also bought a defective one. I would recommend any good brand that feels good in your hands. (Dewalt, Milwaukee, Makita, etc.)
John
