Dewalt was my go to tool brand for many years, we used to say: "If it's not yellow and black, send it back" unfortunately the 12v and 18v Nicad batteries were junk.
I switched to Makita 18v Lithium Ions when I realized how much better the batteries were, and I switched over to Milwaukee when I realized their batteries were almost as good as the Makitas, but they had, for my purposes, a better selection of tools.
My cordless tools are mostly all Milwaukee, except we still use Makita impact guns and drills.
My Dewalt battery tools are almost all gone, every year when my local tool supplier has a trade in deal I give him a handful of dewalt tools in exchange for a pair of batteries or $100 off a Milwaukee kit.