Milwaukee and Makita are owned by the same parent company, there is a bit of crossover as far as technology is concerned.
Makita introduced the first commercial cordless drill, and tends to be a half step ahead in others when it comes to batteries and motors--which is the most important parts of cordless drill/drivers. Makita batteries will last longer.
Milwaukee makes very good stuff, the quality of the rest of the tool (besides battery and motor) seems to be a tad better than Makita.
Dewalt is generally a few dollars less, and offered the bang-for-the-buck factor. After suffering a bit during the recession,, Dewalt has come back strong and is offering a lot of new, useful tools currently.
Ryobi isn't bad, the batteries are shorter lived than the above brands.
I really wouldn't mess with Rigid.
Panasonic, Hitachi, and Porter Cable aren't bad, but their cordless tools are a step behind the big three these days.
Pick your favorite color, pick a battery voltage (although I think some of the DeWalt stuff can run either 20v or 18v batteries), and stick with the same brand and battery--it makes life more simple.
The bigger the battery, the heavier the tool.
Couple things: KEEP YOUR BATTERIES CHARGED. It makes them last longer. Don't deplete them and then throw 'em in the corner and let them sit. Don't let them freeze. A fully charged battery doesn't freeze as easily as a depleted battery.
The lithium batteries have a chip in them to communicate with the charger and not allow the lithium batteries to melt down when things go wrong (see Boeing). There is a minimum voltage threshold and if the battery is depleted, freezes, drops the voltage below that minimum threshold, it permanently shuts down the battery. The Makitas have the most sophisticated chip and are the first to shut off the battery--there is no way to undo it, either.
I have a Craftsman kit I bought a while back 18v ni-cad.
The batteries all went toes up, the tools are fine.
So, I bought a drill, and something else to get the lithium batteries that come with them (cheaper then buying batteries)
Last weekend i need a drill, every battery but one is stone dead. Even one i left in the "wont overcharge and kill the battery charger".
Could this be from a chip.
Cordless is great for me. I might do a project that is intensive, but most use is less than one battery charge.
I am done. I have a 12v Milwaukee drill that's perfect, except no batteries.
Now 6 or eight lightly used worthless tools more.
Convience be damned I'm back to extension cords.
