I have just brought this today and have alreay listened to it twice. I love it. The opening theme is one of the best opening themes in television history (so much better then Star Trek, Doctor Who and even more so, it is better then Gray's own theme to Thunderbirds).
The episodes that Gray wrote full scores for are some of my favourite episodes, so when listening to the music, it is very eay to visualise what would be happening were I watching the actual show (especially Breakway and Matter of Life and Death).
One of the best pieces of music on this CD was not actually written by Gray, but adapted by him for the episode "The Testament of Arkadia" It is probably the most beautiful pieces music I have ever listened to and the vocal harmonies towards the end just blew me away.
One reviewer said that this CD isn't that great because it represents a claustrophobic feel towards the series on the moon being blasted out of orbit and being sent off into space. I feel that adds to the genius of Barry Gray and the orchestral feel that is presented on this soundtrack allows you to take in that feeling of being on Alpha.
I think everyone should buy this CD but if you are a fan of Barry Gray and of Space 1999, then you should definetly buy it.