According to Amazon, Kindle users buy 2.6 times as many books as other customers - and even purchase the same number of printed books that they did before. So why did one attendee of Book Expo America last month confess to wanting to punch an owner of the ebook reader?

My guess would be he’s a bookshop owner. Buying a book (or magazine or blog) on the new Amazon Kindle DX is as easy and as tempting as ploughing through a whole packet of Hob-Nobs in one sitting. The 3G wireless link is faster and more reliable than ever, presenting a great looking Kindle store with most bestsellers at half the price of traditional bookshops - all available to start reading in moments, day or night.

The larger, 9.7-screen will appeal to almost everyone, from lazy readers like myself who enjoy small fonts and a minimum of (still annoying) flickering page turns, to older readers who can finally fit more than a handful of large-print lines on one screen. The DX retains the Kindle 2’s iPod-alike smooth edges and brushed metal back, but now you’ll need two hands to manage its half-kilo weight. The smart leather cover with a magnetic latch ($50) is a must-have accessory.

Unfortunately, the DX also keeps its smaller sibling’s tiny, sharp joystick and cheap-feeling page turn buttons. The keyboard is fine for tapping in URLs on the (very, very basic) web browser but Amazon was wise to avoid any feature creep - it’s too flat and unresponsive for email, say.

The auto-rotating screen is more of an annoyance than an advance - it’s very slow to spin, books look plain weird and both websites and newspapers still display in a single column. Some PDFs (which the Kindle now reads natively) do look better in landscape mode, although you can’t zoom in, rotate or manipulate these files. At least you can turn the rotate function off.

With the extra Flash memory (now up to 3.3GB), it’s astonishing that Amazon hasn’t overhauled the Home screen, which still shows a single list of everything on the reader, sorted by date. Get more than a couple of dozen items on-board and it becomes a real mess. At least a decent search function helps you locate items, and look up words in the dictionary or online.

Away from pure reading, the text-to-speech function might be helpful for some readers (although not blind users, as it doesn’t work on the Home screen and menus), while the background MP3 player sounds better than expected, especially through headphones.

Battery life is fantastic - I’ve charged the DX once since getting it a couple of weeks ago – and the build quality feels very solid. But, unlike my old Kindle 1.0, the DX hasn’t shifted from the sofa: it’s just too large and cumbersome to find its way into my bag for day trips.