I bought this to replace a truly crappy Shark rechargeable vacuum. The DeWalt was one of four that I had decided on (the other three being the B&D PHV1800, Eureka 71A, and B&D CHV1500 in descending order of price). I ultimately chose the DeWalt because it uses a standard DeWalt power tool battery, has a washable filter, and was the only wet/dry vacuum of my selections.
The box contains the vacuum itself, rechargeable battery, fast charger (will charge a completely flat battery in about an hour), and a thin but complete owner's manual.
The DeWalt's design is all business. It's about the size of two irons or half a shoe box. The top has a very grippy rubberized handle that's set above a large (but not stiff) responsive power switch. It's very easy to turn the vacuum on and off with one hand and very difficult to do so accidentally. A plastic vacuum hose runs from the back of the unit over the top (the handle) to the vacuum nozzle on the front of the unit. You can easily pull the hose out of the nozzle to get into smaller crevices; put the hose back in and it's a normal hand vacuum. Underneath, in the back you've got a black plastic debris bin that's held in place with a beefy (but, again, not too stiff) latch. In front of that is the standard DeWalt battery pack.
Although it's one of the heavier vacuums out there, the weight is well balanced. You can easily tilt the vacuum in all directions without feeling like you're fighting the weight of the battery and/or the vacuum motor. You can vacuum vertical surfaces just as easily as horizontal ones. You CAN use the vacuum vertically if there's water in the collection bin; the bin seals tightly enough to the base that leakage isn't a problem. However, having too much water in there could make it splash into the motor assembly. So the moral is: If you've got water in the collection bin, empty it out before doing anything vertical (or hold the vacuum horizontal and use the detachable hose).
So, how well does it work? Quite well, in fact. The motor is very powerful and was able to easily pick up all manner of bits that I threw at it including drywall dust, small finishing nails, screw anchors, and cat hair from a wood floor. It also did an excellent job removing cat hair from upholstery despite its lack of a power brush or upholstery comb. In the car, it easily picked up all the sand, dirt, pebbles and occasional penny without any complaints, including bits that were embedded in a damp carpeted floor mat.
Emptying the bin is simplicity itself and takes less than five seconds to complete. The filter seems to be doing an excellent job so far; even with a bin full of drywall dust, there's no "cloud" when you turn the vacuum on again. I haven't yet needed to clean the filter but it's easily removable and is washable. (EDIT 03-24-08: I finally had to wash the filter. It lost about 70% of its suction after pulling up a buttload of spackle dust, so I removed and tapped the filter against the inside of a trash can. A HUGE cloud of dust was released. About a minute at the sink with a small stiff bristled scrub brush and the filter came clean. I let it dry overnight before reinstalling it; meanwhile I rinsed out the collection bin and cleaned up the unit itself. By morning it was back to its old self again, sucking up everything and scaring the cats.)
The battery lasts friggin' forever. Out of the box the battery had a partial charge on it that lasted about 20 minutes. After charging for about half an hour in the included charger I was able to vacuum pretty much every corner and edge in the house, plus my car, without losing any vacuum strength. A big selling point for me was that it uses standard DeWalt power tool batteries so finding replacements will be incredibly easy.
My only real issue with the vacuum is one that has been mentioned before: This vacuum is LOUD and does emit a power tool-like whine which some people can find annoying. I doubt it's any louder than my full-size vacuum cleaner but since it's held in your hand rather than being dragged on the floor, it's closer to your ears and therefore might sound louder. So far as 18v handheld vacuums I compared it against this one is about average in noise, and compared to all handheld vacuums I looked at this is definitely one of the louder ones. I therefore wouldn't consider this to be "bad design" but simply a consequence of a larger and more powerful motor. Even so, since there are other 18v handhelds out there which aren't as loud, I think DeWalt could have done a little something to quiet it down just a little more.
I also would have liked to have a transparent debris bin so that I could see how full it was. This feature exists on at least 2/3 of the handheld vacuums out there today. I recognize DeWalt's "yellow and black" design decision here probably overrode this as a possible feature.
The only other thing I would have liked to see on this vacuum is a few more accessories; namely, a shoulder strap (so you can walk around using the hose to clean things like window sills and such) and a few hose accessories like an upholstery brush or pinhole nozzle. Still, even with these minor shortcomings I'd definitely buy this one again.