Virgin Media's new cable TV box can play all free-to-air HDTV channels in the UK. The trouble is, there is only one - the BBC HD trial channel. To compensate, Virgin Media supplies a huge and ever-changing library of on-demand HD programming that you can dip into at any time.

The success of this model depends entirely on what material is provided and how often it changes, of course. At present there's a smattering of movies and a vast library of documentaries regularly shown on BBC HD, including Planet Earth, Blue Planet and Bleak House. If you're only after HDTV, you've reached a dead end, although Virgin promises to double the HD library to 700 hours by the year end.

But then Virgin Media's brand new V Plus Box HD was never designed to be a HDTV receiver per se. Check out the company's recent advertising and you'll barely see a mention of HDTV. That's because V Plus also happens to be perhaps the best personal video recorder around and that's its key selling point.

Similar to Sky Plus or SkyHD in many ways, the V Plus Box has a 160GB hard disk, HDMI output, component video, two RGB Scarts, stereo audio outputs, RF in and out and an optical audio output for surround sound duties. There's also an Ethernet port for broadband, a service-only USB and a Serial ATA for any future external expansion of the hard-disk capacity.

A great remote control that's almost as good as Sky's helps navigate the potentially confusing platform. Controlling the volume of most TVs, the remote also gives one-button access to your library of recordings on the hard disk. But while scanning through the EPG to find programmes to record works easily enough, some functions can be frustratingly slow.

It's that extra TV tuner and a truly vast library of on-demand material in standard definition that sets it apart from Sky, as well as its ability to record two channels while watching a third.

Archiving recordings is also a cinch. Just set up a playlist and add what you want to export (the box tells you how many minutes each recording will take up), then connect a DVD recorder.

At 90 minutes, Virgin has a slightly longer 'pause live TV' mode, while the ondemand portion of the service is brilliant. There's a 'watch again' library of programmes screened in the last week, but it's the comedy library (entire series of Brass Eye, Comic Strip Presents and Green Wing) that we liked most.

During our test, the HD movies menu contained A Knight's Tale, Hoodwinked, Kill Bill Vol.1 and Severance (all £3 or £4) as well as BBC HD's How to Build A Human, Pride, Superhuman, Blue Planet, Magic Flute and Wild Weather. We also noticed that four episodes of the live music showcase London Live were available via HDMI only, which indicated the appearance of copyright protection.

Shown in both 720p and 1080i formats, hi-def content looks fantastic with vivid colours and sharp, precise details particularly on the BBC HD stuff. The V Plus box also deals in Dolby Digital 5.1 surround sound, which proves useful for some of the BBC HD material.

The Virgin service is restricted to those living in cabled areas at present, although there are plans to do an IPTV service to non-cabled areas next year - but it's unlikely to offer the hi-def element. Fans of Sky's sports channels in any quality should look elsewhere.