For us this unit will serve mostly as an emergency power source for lights and for charging small electronics. The jump starting and air inflating features are bonuses and great resources to have.At first glimpse one can see the thoughtful design of the Energizer unit. The air, jump, and power features are clearly marked on the front A button to check available power is large, green, intuitive; unlike my Black and Decker power station, the color coded jumper cables are attached to system, one on each side. Each cable is designated with a large, readily visible plus or minus. For one not sure of the jump procedure, the steps are numbered on the Energizer with large numbers 1-2-3.Atop the unit is a lamp with flexible neck aglow with four LED bulbs.I haven't jump started a car with this particular unit yet, but I have used a similar unit for this purpose and it is wonderful to be able to do so without a second car. On brutally cold days, the Energizer will be riding shotgun with me.The portability of the air inflator is also very welcome. I've used units that plug into the cigarette lighter and require jockeying a cord while moving from tire to tire. Using this unit to inflate is fabulous. I did notice that the inflation is a tad slower with this Energizer than it is with my beefier Black and Decker 400 Unit.We haven't had a power outage yet so I had to simulate one. The Energizer powered a floor lamp for about five hours before losing steam. I had hoped for more juice. It also was able to power a small TV and a DVD player, but not at the same time. It could not run the power staple gun or an electric drill. A small cooling fan is readily audible when the power is on, but in a real electricity outage I don't think we'll mind the steady hum of the fan.The Energizer 84020 is great for the occasional jump start or as a standby to keep the car tires properly inflated - so much better than trying to find an air pump at a gas station. As a back up power source, probably not its prime intent, the Energizer is only adequate for light duty which is why I bought the Black and Decker to supplement its limited power. If I were to buy a third portable power unit, it would be something like the Duracell 600HD powerpack which offers 600W  peak A/C power.