Bookeen's previous eBook reader, the original Cybook, was a rather plain device and didn't feel very tough. The Opus is more stylish, with graceful curves and a two-tone colour scheme. Despite being very light it feels well-built, with firm, responsive buttons and a stiff case. It's smaller than the original Cybook, with a 5in screen, but it has a built-in accelerometer, so you can flip it to landscape mode to have more width on the page.

The Opus shares the original Cybook's inability to scale PDF files - you can zoom in and out, but the text doesn't reflow to fit the screen. The Opus, unlike the original Cybook, doesn't have Mobipocket PRC support, but still works with the more open ePub format and PDF files. It's also lost the ability to play music, which is a dubious use for an eReader anyway.

The accelerometer is a welcome addition, however, and works really well. You can turn the Opus in any direction and the screen will redraw to match your view. What's really clever is that all the controls change to match the orientation, and always behave as you'd expect - whichever page button is "top" or "right" will go to the next page, and the "bottom" or "left" button will go to the previous page, no matter which way around you hold the Opus.

The control system is minimal but practical. Two buttons to the right of the screen (in standard portrait mode) handle page navigation, and there's a four-way navigation wheel with a button at its centre below the screen, which is primarily used for navigating the menu system but can also be used for page navigation. The menu is activated by a dedicated button, and then there's a back button to return to the previous option or screen.

With twice the internal memory of the Cybook and an SDHC card slot for up to 32GB more storage space, you shouldn't have to worry about running out of space for books. The internal storage alone is enough for hundreds of titles, but having a memory card slot is a bonus as it means you can share the Opus with family members and simply swap out the card containing your library for theirs.

We enjoyed using the Opus more than most other readers due to its low weight - at 150g, it's 26g lighter than the original Cybook, and almost half the weight of the Sony Reader and Amazon Kindle. It can easily be held in one hand for long periods, and the accelerometer means that whether you're right- or left-handed you can find an orientation and button layout that suits you.

You don't get wireless access to a bookstore as you would with the Kindle, but having said that you're not tying yourself into Amazon's proprietary system. If you decide to upgrade to a new eReader in the future, you can easily transfer your books across. Bookeen recommends using BooksOnBoard.com for buying ebooks, which has a dedicated UK site with detailed instructions for installing Adobe Digital Editions, its preferred library software.

Although it's quite a simple device, the Opus is pleasant to look at and use, and uses open formats and standards so it won't lock you into one company's products in future. Our only concern is price, as we feel £200 is still too much to pay for an eReader.