For the everyday home cook there is no reason, I would point you towards the Victorinox Fibrox range and a ceramic water wheel sharpener. On the other hand they are beautiful bits of kit and if you do cook a lot and have got some cash to spunk then they are great and will last a lifetime. Most people who have global knives for home use can't keep them sharp enough to make it worthwhile though really. I would say it took me about two years of being a pro cook to learn how to hone an edge on a knife using a steel and I still can't use a stone to sharpen a knife effectively (sharpening and honing being two different things, but lets not go there). Also, in the grand scheme of things the price of a Global knife is not that expensive, look on the japanese knife company's website at how much it costs to get a proper hand mand japanese blade, the prices are truly eye popping.
Also, I would say to people never to buy a set of knives. Really there are only about 5 knives you need to cover every job your ever likely to do in a pro kitchen let alone a home one, anything else is just greed (I should qualify here by admitting I probably have between 20 and 30 knives, you get adddicted to them). These knives rarely come together as a set. A cooks knife, a boning knife with a bit of flex, a serrated pastry knife, a carving knife and either a turning knife or a paring knife will cover pretty much every cutting job you can imagine. Add to that a step pallet knife (not actually a knife), a speed peeler and one or two other bits and bobs and that's basically you set.
Still, them knifes are awful appealing....
). After that ask to have a look at them up close, have a feel of them, see how they feel in your hand. 
enjoy
