I have had a hard time with this very topic. We use cordless drills and impacts 6 days a week in the shop. We drill holes through hardened truck frames very often and 1/8-1/2" mild steel plate every day. We take nuts off rusted bolts 6 days a week with the cordless impact drivers every day as well.
I have gone round and round with which one is best. Here's the deal, there isn't a best one. They all have their drawbacks.
We started with an 18 volt lithium Dewalt drill and impact driver set. The drill has an all metal chuck. That's important. With a fresh battery the drill will hurt you when the bit hangs up in steel. After a year it still would.
After about a year the chuck was worn out. Bit's slipped in it.
I researched the best one on the market. Supposed to be the Milwaukee Fuel. I ordered one. It came in. I put a brand new 1/2" Norseman drill bit in it, set down on a piece of 1/2" plate and laid on it. Half way through drilling the hole, the drill stopped and the clutch started popping even though it was on drill and not set to slip. Back it went. The replacement was not one bit better. I could stop the Milwaukee and the one year old Dewalt would still twist your arm double over.
I will NEVER own another Makita tool. My dad has some of their cordless stuff and has had to have the clutch replaced twice in his drill with moderate to heavy homeowner use.
The Makita rep came by our shop and after his song and dance talked me into buying one of his 4 1/2" angle grinders that "couldn't be burned up" due to some sort of slip clutch in the head. The day I got it I called him and told him the head of the grinder was getting so hot while using it that you couldn't hold it bare handed. Three months later, smoke came boiling out of the motor while I was using it. It's sent back right now. I better get a new one.
The Metabo rep came by the shop a month or so ago. He was pushing his grinders, which I don't like, and showed me his super duper heavy duty 1/2" cordless drill. I told him I would buy one on the spot if it worked like I wanted it to. I grabbed a new drill bit, started drilling a hole in 1/2" plate and the drill completely stopped halfway through the hole.
So, I have been round and round. Buy a dewalt with an all metal chuck and run it til it won't run anymore. I bought another Dewalt set a month or two ago. The chuck already slips.
If Dewalt would step up and match Milwaukee, Makita and Metabo's battery warranty they would own the cordless market.
2 side notes: 1) I didn't mean to get on my soap box.
2) If you want a good angle grinder, get a Milwaukee.
