I refer in these comments to the full 3-video mini-series, not the truncated version or film produced for the American market.
In general, a well-produced and directed series which, with a few minor exceptions is probably as close to the true horror and carnage of the First World War as it is possible to get. Most of the minor errors can be explained by the requirements of plotting or pure visual effect and, in my opinion do not seriously detract from the overall truth of the subject matter.
It should be remembered that this series was produced for the Australians, whose culture and memory is very different to that of the Americans who seem to have a collective down on this video/film. Perhaps if our North American cousins had come into the war several years earlier and suffered the casualties the Empire did they might have a different view of the series.
The feeling throughout the series is of the AIF being abused and butchered by the incompetent British generals - and as a military historian I cannot say the series is wrong. However, other than one short scene, the series does not highlight the fact that the British were suffering just as much under their own generals.
All in all I would say the viewer would get a much better idea of what the AIF and World War I was about by seeing this mini series than by viewing Gallipoli, which is generally thought to be historically weak.
I would recommend the mini series but not the film or truncated North American video release.