Our overall favorite is the Makita LXDT01. It's fast, light, and powerful and has excellent runtime. The grip is very comfortable and the 5.5-inch head length makes it the shortest tool tested.
We also like the Hilti and Milwaukee tools, both of which are available with full-size or compact batteries. The Hilti is fast and has exceptionally good runtime; it placed first in the runtime test and second in the timed driving test. Convenience features include a battery gauge and variable output settings.
The Milwaukee is the brute of the bunch – a fast, powerful tool that torques noticeably when you engage the trigger. It came in first in the timed driving test and third in the runtime test. We like the battery gauge and robust wire-bale belt hook.
Greg DiBernardo owns Fine Home Improvements of Waldwick in Waldwick, N.J.
This driver is available in two different kits – the 25618-01 (with standard batteries) and the 25618-02 (with compact batteries). A well-balanced tool, it has a responsive trigger and a comfortable grip. The single light under the chuck does a good job illuminating the work but does not have a delayed-off function. The well-designed hard plastic case is perfectly sized to fit the tool and accessories without taking up too much space. Both kits are worthy contenders.
Bosch's 26618 is a hybrid – a combination of a two-speed drill and an impact driver. To change between modes, the operator shifts a switch on top of the housing. It's an interesting idea, but try as I might, I am unable to come up with a good reason for a hybrid tool. If I want to drill, I would rather use a drill/driver and a standard bit than have to handle a big, heavy combo tool and keep hex-shank drill bits on hand. I do like the three-LED light on the nose of the tool. ]
These two kits contain the same tool with different battery packs – full-size batteries in the DC827KL and compact ones in the DCF826KL. With either battery, the tool itself is light, compact, and well-balanced. It has a responsive trigger and was among the leaders in terms of driving speed. Since it's compatible with DeWalt's older XRP tower-style packs, it will integrate into the company's existing systems. There are a couple of things we don't like about this impact driver: The belt hook must be purchased separately; and when the batteries are low they cut out immediately instead of fading slowly, so you can't squeeze out a few extra fasteners.
This 20-volt Max series tool arrived too late for us to test. Lighter and more compact than previous DeWalt models, it takes the company's new 18-volt slide-style lithium-ion batteries. Features include a belt hook, a one-handed chuck, and a three-LED light with a 20-second delayed-off function. Shown here with a 1.5 Ah compact battery, it also takes a 3.0 Ah standard battery.
HILTI SID 18-A
The SID 18-A is one of my favorites, a feature-packed tool with exceptional runtime and superior driving speed. With the standard battery, it placed first in our runtime test, and with the compact battery (SID 18-A Compact) it beat all the other tools with compact batteries. With either battery it was among the best performers in our driving-speed test. Features include variable-power output, a battery gauge, one-handed bit loading, and a bright four-LED light surrounding the nose. The belt hook – which we didn't get – is a $9 accessory. This model is scheduled for release in January 2012; we tested a prototype.
This tool is light and comfortable to handle but has a longer head than most other impact drivers. In the field it ran longer than expected for a tool with a compact battery, and in the runtime test it beat all but one of the tools with compact batteries. It placed near the middle of the pack in our timed driving test. For someone on a budget – who isn't already committed to another battery system – it would be a reasonable choice. It comes with a small plastic case that makes efficient use of storage space.
Though one of the longer, heavier tools tested, the WH18DL is reasonably comfortable to handle. It's best for larger hands, because the grip flares at the bottom to accept the thick post of a tower-style battery. Added features include a bit holder and a two-position variable-output switch on the handle. The light is built into a pivoting plastic belt hook and must be manually activated. The durability of this hook is questionable – and unless you go to the trouble to fold it down, it's in the way when you use the tool left-handed. The tool performed in the middle of the pack and has too many odd and awkward quirks for me to recommend it.
The BTD141 is light for a tool with a full-size battery, and very compact. It feels fast and powerful in use and was a solid performer in our runtime test, placing fifth. The light does a good job illuminating the work area and remains on for 10 seconds after the trigger is released. The trigger is very responsive, and you can load bits without pulling the chuck collar. The only thing I don't like about this tool is the blow-molded case, which is large and unnecessarily bulky.