Useful to keep in the boot and small enough to not get in the way.
Power cable (cigarette lighter style) is a good length to reach front and rear tyres (have to switch door/window you put it through to switch sides). It can also be coiled (has to be neat though) and fits in to a compartment on rear. Same can be said for airline but it coils into a recess on one end. The end of the airline has a screw type adapter and creates a good seal to valve.
There is a LED torch on one end that has proven useful when I lost the valve cap in the dark, however it doesn't have (or really need) a very long range.
The LCD display is lit and easily legible and can be switched between psi, BAR, etc.
Plug it in, connect airline to tyre, check current pressure (reasonably accurate but prefer a dedicated gauge for final check), set desired pressure and hit on button. It seems to inflate to a pressure slightly above set pressure, possibly to allow for any leakage as you unscrew airline and then stops the pump.
The pump will remember the last set pressure so if you're doing multiple cars (bloody family) double check what you need.
As for reliability, I've used this numerous times over the last 12-18 months (occasionally multiple times I one day) it's still going strong. If you're running it for long periods or repeatedly allow it to cool down as the airline will get quite hot. Heat production is a natural side product of compressing air.
A good pump for a good price.
Nearly 3 years on and besides picking up a few scratches and one of the small rubber pads on the back (act like feet) vanishing it still works perfectly.
I've seen a few identical pumps with the only difference being the branding, not sure if quality is the same/worse/better but if you look around you might find a good deal.