From £269.

Positives: Apple build quality paired with an extensive, vibrant app market.

Negatives: against stiff competition it's £100 too expensive and the wrong shape.

Two years ago, responding to the wave of 7in tablets that were beginning to eat into the 10in iPad's market, Apple CEO Steve Jobs famously quipped: "This size is useless unless you include sandpaper so users can sand their fingers down to a quarter of their size."

But fresh competition this summer from Amazon's Kindle Fire HD and Google's Nexus 7 forced the tech giant to react. Apple's answer is the iPad Mini, a 7.9in tablet with the same button layout, dual cameras and 10-hour battery life of its big brother.

Understanding that independent developers may be reluctant to reshape their apps for yet another screen size (the iPhone 5 brought the total to seven), Apple has chosen to squeeze the pixels of last year's iPad 2 into a display that is two inches smaller. The result is a machine that looks, feels and works exactly like any other iPad, just "further away" as Father Ted might say.

On paper it's a sound approach. The iPad is – undisputedly – the best tablet on the market and if customers want a smaller one, why not let them have it?

In practice, though, it's not that simple. The original iPad was an incredibly clever piece of industrial design. It took rivals years to understand the subtleties that made the iPad better than every other tablet, and most rivals still fall short.

Key to its success was the 10in screen that allowed a full-size, millimetre-perfect reproduction of a desktop computer keyboard. Even without the feedback of physical keys, computer users could pick up an iPad and type quickly without many mistakes.

On the iPad Mini's screen that same keyboard is 20% smaller, which makes touch-typing virtually impossible. Too small to operate with all your fingers yet too big to operate phone-like with thumbs, the Mini forces even experienced typists to hunt and peck for individual letters.

Perhaps that's irrelevant. Perhaps a 7in device is only intended for content consumption – watching videos, playing games and reading e-books – not writing essays.

On that basis the iPad Mini makes a lot more sense. It'll fit comfortably in a large pocket or a small bag, ready to entertain on the train or in the coffee shop. But here, too, it's compromised. The 4:3 ratio of the screen is the same as pre-widescreen televisions of the 1980s. As a result, modern widescreen movies and TV shows occupy a relatively thin strip in the middle of the screen with thick black bars above and below – videos are no larger on the iPad Mini than on the smaller but more sensibly proportioned Nexus 7 and Kindle Fire.