How can you give bucketloads of stars to a product when its own manual appears to tell you bluntly, in two languages, that it doesn't do a proper job...I was impressed with the multiple purification technologies, clean, under-stated design, unobtrusive colouring and especially the minimalistic operating lights - two or three tiny LEDs, which are greatly to be preferred to the ostentatious (but efficient) Fellowes with its nocturnal resemblance to the Blackpool Illuminations. Although there are a few minor issues.First, the air exhaust is fixed to discharge only upwards, whilst many prefer the facility of directional adjustment.Secondly, you can't switch off the ioniser, and whatever its merits, many mistrust or dislike it.Thirdly, the choice of pinhole type switches (as, eg, you find for reset purposes on routers) is puzzling; who wants to go hunting for a pin when you want to press a switch ? I found them lacking any positive engagement, and difficult to locate in their holes. It's also easy to attempt to press in the wrong hole initially - and there are ten, all superficially identical, some containing LEDs, others switches, each with only a tiny, single-word, not always intuitive label, invisible in low lighting (white on grey) with no indication of which are switches and which are LEDs.However, it's at least very quiet on both low and medium settings, although on max, it's too loud for music or TV.Now to the major issue.I disbelieved one reviewer's reference to a seeming peculiar disadvantage, which I didn't think could possibly be right. But he's not only right - it's even worse - my profuse apologies to DaveW...To quote the manual, "THIS UNIT WILL NOT BE ABLE TO OPERATE EFFECTIVELY, IF IT IS PLUGGED IN WHILE INDOOR AIR IS POLLUTED" - Silly old me! There was I thinking that removing existing pollution was what these gadgets were for... In further explanation, the manual adds that on startup, it measures the existing air conditions, and defines them as "clean air" - which appears to say that your existing pol