>I honestly can’t see a reason for Joe Soap to favour one over, say, the Nexus 7
Software, software, and the odd bit of hardware. Most people will have their needs met by the range of apps available on Android, but there are some who will be better served by iOS - particularly in the area of music creation. More annoyingly for me (I'm an Android user) is the range of 3rd party hardware that is designed to work with iDevices (most commonly, the remote controls on wired headsets - and there is no one single Android system; even a single vendor like Sony have released Android devices with slightly different headset implementations), and hardware that works in conjunction with apps only available for iOS (some DSLRs, Adobe's upcoming Napoleon Ruler and Mighty Pen)
The converse is also true; there is no waterproof iDevice, none with built in IR, none that has NFC (though its a feature I've never used on my phone).
It's up to the individual user to asses their own wants. and decide if its worth the £100+ price difference.
(Though the Reg is not guilty of this, I'm getting bored of reading reviews of smartphone apps and games on tech-sites, and only reading at the end of the piece that it is available for iOS)