Since it was launched in 2001, the Sky PVR has become the UK's de facto digital recorder standard. After targeting early adopters, the company has been aiming its Sky device squarely at the mass-market. The price of the box (and installation) has been reduced from the original £400 to £100 - although you need to be a new subscriber, and prepared to cough up for the full Sky World and Family package (£41 per month).

Existing subscribers pay £200 (at the time of writing there was a special offer of £150) plus an installation charge of £60. The latter, however, is waived if you decide to use your existing box in a 'Multiroom' configuration - which conveniently duplicates your chosen package in another location within the house for an extra £10 per month.

Sky has also brought down the costs in that there's no subscription fee if you subscribe to at least one premium channel (movies or sports). Most Sky subscribers, fortunately, tend to fall into this camp.

So why has Sky proved such a hit? Simply put, once you've lived with Sky it's difficult to imagine life without it. You can schedule recordings directly from Sky's easy-to-use EPG, and - thanks to the Series Link functionality, it can be told to automatically record all episodes of a favourite show (be warned, though, the Series Link is not infallible, and not supported by all broadcasters).

As Sky stores the channel's datastream on an internal PC-like hard disk, what you're effectively watching during replay is the original transmission - hence no quality loss whatsoever.

The Sky incorporates two tuners, so you can simultaneously record two channels (TV or radio) on different channels, or watch one channel while another is recording. Pausing live TV is also possible, because the Sky is always buffering the channel that it's currently displaying.

If you decide you want to keep the recording, it will save the entire programme (or at least part of it, depending on when you last changed channels). This recording - and any others - can be accessed via the Sky Planner, which you'll find as the last option on the expanded TV Guide.

Then there's the issue of connectivity. The Sky is the only digibox device to offer a Dolby Digital-compatible optical digital output. This comes into its own if you subscribe to one or more of the movie channels. Many of the films broadcast are transmitted with Dolby Digital 5.1, which can be enjoyed with the appropriate AV kit. Even if the movie channels don't appeal, you still get better sound from regular TV channels; it's also useful for those who want to record radio programmes on to digital audio media.

The Sky is also unusual in that an S-video output is offered - handy for those whose DVD recorders don't have an RGB input. On which subject, Sky offers a handy multiple copy function. From the Sky Planner, highlight all the recordings you want to transfer to DVD and the Sky will play them all in sequence.

This is a distinct boon if you have a DVD recorder with in-built hard disk; you can then split up the recordings and edit out any adverts, trails or stray bits of other programmes before copying the results on to a DVD-R or DVD R for long term archiving.

Improved capacity

Since the original Sky (and its functionally-identical but smaller 'version 2' follow-up) was launched, we have only had one real criticism of the system. With all of the channels that are now available, the 40GB capacity - enough for approximately 20 hours - is now proving to be a drawback.

In 2001, a 40GB hard disk was probably one of the biggest you could buy without breaking the bank. Since then, however, capacities have multiplied. 200GB drives - 5x the Sky 's capacity, or potentially 100hrs of recording - are sold by computer retailers for less than £100.

It's no wonder, then, that some Sky owners decided to 'super size' their hardware. As regular readers will know, it's quite a straightforward task to replace the 40GB hard disk with one of larger capacity. Apparently, with Sky's latest firmware upgrades (1.31A8), drives of up to 250GB are now recognised for up to programme archives totalling 125hrs!

These firmware updates also appear to have killed the so-called 17-minute 'bug', in which random recordings made on upgraded Sky units could not be accessed beyond the 17-minute point (they would, however, usually play 'normally' for up to an hour until the picture freezes altogether - beyond which further playback is impossible).

Opening up a Sky does, of course, invalidate any warranty. For this reason, many are put off the idea altogether. Just as well, then, that Sky is now selling an expanded version with a 160GB hard disk for £400 (plus the installation costs outlined earlier). £400 is, of course, the same price of the original when first launched (note that the 40GB version will continue to be available). The Sky 160 will allow up to 80hrs of TV recordings to be stored - enough to make any digital TV junkie salivate.

But there's more to the new model than a bigger hard drive. Although the box looks similar to a standard version 2 box, albeit with '160' front-panel decorations - there is now USB 2.0 connectivity. There are front and rear sockets, but the supplied manual makes no reference to them. So what are their purpose? Sky's consumer PR executive would only say that the USB port on the Sky 160 is for future developments, for which they have no current plans.

Fair game?

There's an obvious possibility they might be used for gaming controllers or keyboards. But that would be the mere tip of the iceberg. At the recent IBC (broadcast TV) conference in Amsterdam, News Datacom showed content being copied from a USB-enabled Sky to a personal hard-disk video player.

The video player in question was the Lyra from Thomson (Thomson also makes the Sky 160 ). Sky plans to market this new kit as Sky To Go, sometime during the latter half of 2005. Another interesting application saw video content being 'streamed' from a Sky to a cigarette box-sized AV media receiver. This would plug into a TV via Scart, a handset in the remote location being used to choose recordings from the Sky planner for playback.

It couldn't be easier to use Sky . Recent refinements, such as the simultaneous two channel recording mode, and interactive channel recording, are a revelation, and the lack of tape and timers will ensure that the entire family will quickly feel confident about timeshifting their favourite TV shows.

USB and 160GB hard disk aside, there's no discernable difference in the software, hardware or usability from a standard Version 2 Sky device. A component output for projectors and displays would have been appreciated, as this means that a third-generation box will need to be launched to cope with Sky's planned move to a limited HDTV subscription service in 2006.

This latest version of the Sky is more of an evolutionary step than a revolutionary one. The uncharitable might wonder what took Sky so long to satisfy the demand for extra recording capacity, but its arrival is more than worth the wait. If you're into digital TV, then you should get into Sky . It's as simple as that. And life is far too short to contemplate anything smaller than 160GB.