If you've just bought your first iOS device and want to go abroad, then this is great.
If, however, you've got a couple of devices that came with the USB chargers, then if you want to buy just the 'duckhead' plugs, you're spending a lot of money on a charger you don't actually need.
Similarly, given that iPad and iPhone now charge using a Lightening adaptor, the charging lead is also pretty useless.
Thirdly, if you're after just on or two of the adaptors (say, European and US), then you're probably never going to use the others.
It would be a lot more use if Apple sold the 'duckhead' plugs on their own, even in packs of three - if you're going to the US, you could buy just the US adaptors; or if you're going to Australia, you can buy just the Australian adaptors.
Instead, you're going to end up paying for a lot of adaptors you're probably never going to use - and heaven help you if you want to charge an iPhone and an iPad at the same time in somewhere like Australia, because you're going to have to spend £70 just to get two tiny adaptor plugs.
We bought this kit expecting that it would do as it says on the packet, cover the world.
We are going to South Africa and now discover that none of the 6 adapters in the package will cover this major country.