A well-built piece of kit that is easy to operate once you get the knack of setting the tire air pressures. It is very quick to inflate (compared to an old Draper pump), the lighting is excellent, and the screw adapter secure. Having tested the inflation readings they do appear to be very accurate, and the pump makes it a quick and easy job to optimise tire air pressures every couple of weeks. I have not regretted the purchase - I should also mention that the machine is fairly quiet in operation, being far less rattly and loud than my old Draper model. The storage system for the cable is ok, but it is a tad fiddly, hence the four stars rather than the full five, but perhaps I am being overly picky! The pump is easy to stow away in the boot, taking up little space in its holdall.
I would recommend it as a useful addition to any boot.
Addendum, 20th December 2010. I have since purchased a second pump as a practical present - it really is that good - and I would simply echo what I have written above. In use, it has inflated a fully deflated slow-punctured tyre to full inflation with pleasing speed, and the readings given by the Ring continue to be dependable when measured by other devices. Because of its speed in use, I find it a snap to keep my tyre pressures up to the appropriate pressures prior to travelling any major distances, so I suppose that this wee machine is actually helping me to save money as well. If you are in the market for a good pump, then I would recommend this model.