I had one of these systems for years before moving house and chose to purchase another for the new home, what more can I say.
The tap is sturdy and the cartridges easy to change. I find as a small household, the filters would probably last well over a year, no signs of chlorine smell or reduced flow, but I change them as a matter of course.
My only small niggle, is the fittings supplied, I am sure most UK houses now run on 15 mm copper pipe, the fittings supplied are not directly attachable to 15 mm copper, fortunately I have a good stock of random fittings and a 30-minute search solved the problem. How people without knowledge or fittings get on I don't know, just employ a plumber I suppose.