My guess is that if you put a bunch of deck builders in a room and gave them 15 minutes with Hitachi’s new Triple Hammer impact driver, you’d get a mixed bag of opinions. But that’s only because the tool is a bit different from similar impact drivers…which isn’t necessarily a bad thing. The kit I tried last fall – the WH 18DBDL2 – is small and light and ships with two slim-pack 18-volt, 3.0-amp-hour batteries in what I think is one of the very best kit boxes I’ve ever seen.

Ergonomics. I found that the compact driver is comfortable to hold, and I liked the position of the forward/reverse button, which made it easy to reach and engage.

It has a 2-step bit holder. In other words, some bit holders enable you to simply slot the bit into the unit. Others require the second step of pulling the collar forward first. While I prefer a 1-step bit holder, this works just fine.

One feature I really liked is the belt hook. I don’t know how other tool companies manage to flub this, but they do. On this tool, the throat of the hook is wide enough to slot over a pocket on my tool pouch, without being too big. It’s a nice design, and I use it all the time.

Electronics. Hitachi’s approach to checking and changing tool settings is not intuitive, and I had to read the directions (twice, just to be sure) to figure out how it all works. For example, there are four settings for rotation—delicate, power, more power (where I usually use it), and self-tapping. And there are three settings for the built-in work light: On (with a two-minute shut-off); Off; and Trigger-activated. But once I figured out the system, I liked having these options. For example, when I'm working under a deck for attaching a hose bib or some other in-the-dark operation, the constant-on is great for a general work light and a task light.

I also liked the fact that the batteries slide on and off the tool easily, and also into and out of the charger. That isn’t always the case with other cordless tools.

The Box. With some tools, replacing them in their box has become like re-folding a road map, so I was thankful for the diagram that shows exactly how everything should be organized. I don’t think that the box itself will break, but I found that the latches come off easily. However, this small gripe is more than made up for by the fact that the lid has a second tier ideal for the scores of nut-drivers, bit holders, and drives (#2 Robertson, Uni-Drive, star, Phillips, and so on) that are needed for all of the different fasteners found on a jobsite these days.

Performance. From project sites to a week-long blitz-build of my deck and pergola setup at DeckExpo last fall, I bombed in everything from 2-inch screws for gate hardware to 6-inch structural screws to scores of 3-inch #10 deck screws. The Hitachi dug in on every task, leaving no question it has abundant power despite its small (brushless) size to manage any deck-building task. Is it possible I felt it struggle a bit in the 6-inchers? Maybe. That may well be attributable to a waning battery (and a waning me; I work late building those demos). The other carpenters I worked with didn’t notice a hiccup.

I found that the tool’s small size and battery mass absorbed the vibration and torque of impact driving better than other small tools I’ve used. According to the manufacturer, that's because the design adds a third impacting anvil to increase driving speed, beats per minute, and torque, all while decreasing vibration. It’s kind of hard to reconcile quickly (to me anyway), which is why I think you’d get a mixed bag of impressions if you only gave guys 15 minutes with it. But in the weeks that I used the driver, it delivered on all fronts. The kit costs about $400 online.