The answer for me after listening to the New Generation: not at all.
Of course it is interesting to hear the same songs in something aufgepepptem sound. The arrangements are a total of almost 1: 1, the same as the original. There are a few new sound effects, but those who know the old version, which gets absolutely no big surprises. However, there are new voices. And since it has a new version, unfortunately difficult. Let's take the piece 'Spirit of Man': absolutely awesome played and sung in 1978 by Phil Lynnot. The singer now brings not even begin over. Liam Neeson as a speaker does not make it better - but no worse - than Richard Burton. Chris Thompson to replace a singer ('Thunderchild'), does not good. In short: the New Generation wins by the new recording anything. Many effects has taken over without modification Jeff Wayne. Example: the "battle cry" ULLLLAAAAHHH. The gave me back then did not like, because it simply sounds too harmless. In the new version it would have been a chance to make the sound more threatening.
Conclusion: It may be that the sound quality is improved by the more modern technology than the original. When everything else is nothing gained by the new recording. Maybe The New Generation is interesting for those who attend a performance during the tour because the CD corresponds to the sound of the show. Schade: Jeff Wayne would have been open to all ways to add to the story and his musical new pages. This he has not used.
For supporters of the old version: rather invest in a special edition of the original.