The filtering system was way, way better than everything else we had for a very long time and they often also where the cheapest. I write was because honestly I haven't visited many other shops for quite some time. But whenever I check on toppreise it's only marginaly more expensive then the other shops. It's convenient to have everything from the same shop where you know you have it the next day. And the "Geiz ist geil" mentality just doesn't realy exist in Switzerland.