I have been in the electrical trade for over 4 years, and Milwaukee is what I use. The only problem I have had is dropping my impact from a scissor lift 19 feet in the air, which screwed up the permanent magnets. It was a $14 part and ~1 hour of time fixing it. I have 4 year old M18 Li-ion batteries that still hold a respectable charge, although not as good as new.
DeWalt has been coasting on their name lately, and while they still make solid tools, they don't seem to be champing the bit like Bosch or Makita to counter the whirlwind of products Milwaukee has come out with lately for their M18 and M12 line.
Milwaukee's Fuel line is particularly tough to beat, although other top tier manufacturers have thrown brushless into the mix, Milwaukee was planning for it back when they were developing red lithium battery packs. As some may know, a brushless motor is simply a DC stepping motor. They have the advantage of not wasting energy exciting a rotor or stator. Milwaukee was planning to go this route and designed their next gen M18 battery around communicating this load between tool and battery to handle stepper (brushless) motor duty.
I have tools in the Milwaukee Fuel line and have been called a lunatic when old-timers thought I could not put a self-tapper in structural steel. My Fuel impact does it with finesse.
I was told I should wait for the corded Hilti to blast away concrete to get to our stub out. I threw a 5.0Ah battery into my Fuel roto-hammer and cracked concrete that no battery powered ANYTHING should have done.
Greenlee, Wera, and Knipex make the best hand tools, by the way. Klein took a big hit selling to HD, especially in wire stripper department,