I was waiting for one that was under £50 and a pretty colour, and this seemed to fit the bill.
As it turns out, 320 gigabytes is far in excess of my needs: the entire contents of my iMac appear to amount to a frugal 68G, and I could slim it down even more if I got rid of the expired trial copy of Microsoft Office 2001 and sundry other junk.
I was convinced that my computer would explode in the time between my placing the order and the arrival of the shiny, because that's how life works, but I've got away with it. I've installed SuperDuper because there's no way I'll remember to make regular backups myself.
Now there's no need to worry about losing vital files, unless the house burns down.
Even then, the really important stuff gets copied to a memory stick which lives in my trouser pocket.
And if my trousers are on fire, I have better things to worry about than my data.