Bookeen is no newcomer to eReaders, and this is the third Cybook we've reviewed. We praised the Cybook Opus for its lightness and its accelerometer, which allowed you to read in portrait or landscape mode.

As with other open (i.e. non-Amazon) eReaders, the Orizon uses Adobe's Digital Editions to track books you've bought. There's a built-in eBook store, accessible via Wi-Fi and, although it prompts to you to enter a Bookeen account, it's actually after your Adobe ID, which is misleading and can lead to you having two accounts with different books in each.

The store itself is simply a web page, but although the site is in English, only French and German books are currently available, and Bookeen couldn't tell us when the English site will be available. That's fine, as there are plenty of other websites that sell English books, and you can save them to the Orizon's bookmarks for quick access. There are already some bookmarks, such as one for Gutenberg.org which loaded the mobile version of the site and let us download books directly.

While reading a book is fairly lag-free, using the menus and interacting with the on-screen keyboard is sluggish and frustrating. There's little visual feedback to let you know you've activated a control - even the keyboard lacks feedback for each key you press. Although swiping in a book lets you turn pages, it doesn't work in the browser.

One feature carried over from the Opus is an accelerometer. This rotates the screen orientation based on how you hold the device. The controls work contextually, too, so if you switch from portrait to landscape, the 'down' button usefully becomes the 'right' button. You can switch the sensor on or off, but you can't choose which is the default - if you want it to stay in landscape, you have to turn the device to engage landscape mode, and then turn the accelerometer off.

Reading on the Orizon is pleasant enough, although contrast isn't as good on other devices. The 'white' background seemed darker than most other E-Ink screens we've seen. Re-flow in text, HTML and ePub documents was well handled, but in older PDF files where the text is fixed, you get a laggy Zoom control instead. There's no dictionary built-in, which is a shame, although you could potentially switch to the browser and look up words online if you have access to Wi-Fi.

The Orizon's claim to be the world's thinnest eReader may be true, but it's also one of the heavier eReaders around at 246g. Add the weight of a case and you're going to find it uncomfortable to hold in one hand for long periods. Plus, it's silver, black and white colour scheme isn't very attractive.

Compared to the Amazon Kindle , the Orizon seems clumsy. It's partly due to its laggy interface and partly its reliance on Adobe's crude software. The Kobo Wireless eReader is snappier and has far more intuitive interface and - more importantly - it's priced to compete with Amazon's device. Bookeen has promised that its next eReader, the Odyssey, will be more powerful, but the Orizon is frustrating to use, too heavy and too expensive to be a credible rival.