Best cordless is drill is Dewalt (XLR or whatever???). It is also the most expensive. They did well on that. I am a fan of all things Milwaukee... but you pay for it.
In my opinion, if anyone wants it, save the money on the cordless stuff. It doesn't work great as a cruiser/LA and if you are just looking for something when you are part time and at slip, you can use 110v stuff at a tenth of the price and many times the torque. Half the crap ends up in the water anyways. Get yourself a good inverter and some extension cords. Only exception might be when going up the mast.
I have cordless stuff and have pretty much pulled it all off on the boat. Problem is that is needs to stay charged, or like any battery, it begins to lose it. Chraging requires constant power and I have better things to drain power on. A good inverter and a power tool doesn't cost anything to maintain and is a lot cheaper.
That was true of the older cordless stuff that was not LiIon. The newer LiIon batteries hold a charge for months and months. Last winter, around December, I lost an M-12 LiIon battery that had rolled under the seat of my car and I found it in early August. It has been in sub freezing temps and sat at well over 120F in my black interior car for many days. After I found it I slapped it in my tools and continued to use it for quite a while. I also have no clue as to its SOC before I "lost" it but it held its charge just fine for well over 6 months in sub freezing to blistering temps...
Today I don't see much difference in price between Makita, DeWalt, Bosch and Milwaukee. Ryobi, the Lowes "Porter Cable" and Hitachi are a decent step down in price.
Festool and Fein make some incredible tools but are very costly. My Fein Multi-Master is head and shoulders above my Harbor Freight, Dremel and Milwaukee multi-tools but also about twice to three times the price.
Most contractors I see are using DeWalt, Bosch, Milwaukee or Makita. Most use a mix. Surprisingly I see a lot of contractors with Ryobi as well as many boat yards and boat builders, such as Morris Yachts, using it along side more expensive brands such as Fein or Festool....
I don't have a favorite "brand" when it comes to tools. I tend to pick and choose the tool I like for what ever reason, for the job.
Sawzall - Milwuakee & a Porter Cable with a snapped shaft that needs repair
Skill Saws - Makita & DeWalt
Jig Saws - Bosch & DeWalt
Biscuit Joiner - Porter Cable
Routers - Plunge = Bosch, Stationary table mounted = Port Cable
Cordless Tools - Milwaukee, Ryobi and a dead DeWalt that needs repair
Multi-tools - Fein, Harbor Freight, Milwaukee & Dremel
Corded Drills - Milwaukee, Hitachi, Black& Decker
Angle Grinder - DeWalt & Makita
Rotary Buffer - Makita
Small Compressor - Makita
Miter Saw - DeWalt & Delta