Like everybody else have already said, this is a great little device. Two things I like most is the little revolver-type lancet pen with six lancets in it so you only need to change the head once a day or so. Even less often, if what the user Miss B. says is right and you don't need to change lancets every time.
The other thing I love about Accu-Check Aviva Nano is the design: it's sleek and classy, really looking more like a posh electronic toy than a medical appliance! One word of warning: being electronic, it stops functioning at low temperatures. The book says, it stops working and sends an error message under 8 degrees Celsius, but on a few occasions it malfunctioned on me at slightly higher temperatures, too. So be warned if you want to carry it around with you in cool weather: chances are, it'll be too cold to use it.
But that's a small inconvenience, so I give it five stars and wish its developers every success with their future models. Just think how some people can invent and produce such clever and complicated machines -- mind boggles!