Rio Nitrus review

Build quality differs, with the Nitrus feeling as though a little strength has been lost for the sake of smallness. The Karma may look bulky but it's surprisingly compact and feels comfortable in the hand. It's also built like a tank. Battery life was also only bettered by the iRivers and is a major reason for our preferring them to the iPods.

The Karma's docking cradle also boasts some unique features including Ethernet and RCA ports. The former allows you to assign it an IP address - effectively turning it into a media server. The RCA connectors allow you to plug the Karma directly into an amplifier or PC speakers - again, ideal if you want to use it as a media server.

Our only real gripe with both players is the necessity to use the Rio Taxi software to transfer non-music files rather than the player appearing as an external hard drive in Windows. We can't criticise its lack of Windows folder-style organisation, as the entire design and integration of both players is geared to ID3 tags.

As an overall package, if you want a small player with a reasonably large capacity, the Nitrus is the player to go for. If you want a 20GB jukebox with tracks sorted by ID3 tags, and you won't miss the styling of the iPod, choose the Karma.