A little background - I have virtually all the 18v tools that DeWalt has made, including two 18v hammer drills. I have built numerous houses with their tools, and done countless remodeling projects. You could say I'm a fan!
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br /That said, the 36v hammer drill really hasn't impressed me. It is huge, so it doesn't fit in some spaces where the 18v will fit, and the power doesn't seem to be that much better. On the rare occasion that I need something more powerful than the 18v drill, I'm probably reaching for my Milwaukee wrist-wreaker (corded) or a 2" roto-hammer.
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br /I really like the 36v line, and am impressed by the circular saw and recip saw. This drill just seems like a tool without a need. It rarely leaves my shop to go on a job, and I never use it at home either. It was part of a combo promotional kit, so I can't complain about the price, but I don't think I'd buy it outright.

I am a HVAC professional and in my work there are many different drill needs on each job. I love the makita 18volt impact drill for the small screws on the furnaces and A/C units. I am a Dewalt fan and have the 18 volt combo kit as well. I bought the 36volt and use it exclusively for drilling anchor holes in brick and block. I also use it for paddlebit drilling of holes for pulling wire thru the joists in basements and attics. It has plenty of torque and the power lasts a long time. I highly recommend it to anyone that needs a powerful drill without the cord. The only negative I have with the drill is that it sometimes slips out of drill/hammer setting and has to be adjusted.

I bought this with a reciprocal saw on sale for 60% off and I have been rather impressed. The chuck never slips (as cheaper drills do) and the battery lasts for weeks. My only complaints are that the battery seems to suddenly run out of power with little warning (there is no gauge as competitors have) and it is quite heavy.