I don't often vote on polls nowadays, but I wanted to on this. I love this band and I love this boxset. The cds are superb, the remastered studio albums are very clear and excellent sounding, and the numerous live cds are so well mixed, very enjoyable.
From a surround point of view this is difficult to rate. Yes there's only one album in surround and half of that is an upmix. You is my favourite Gong album and one of my favourite albums period. I agree with the comment above, the upmix part is the best upmix I've ever heard, nice and surroundy with lots of discrete stuff going on. And the quad mixes are superb, very clear, discrete and immersive. Up there with the best surround mixes I've heard. For comparison I listened to this earlier straight after the Steven Wilson Farewell To Kings mix, and the Gong You quad shone next to that, which is praise indeed.
If I was voting purely on the quad part it would be a 10 without doubt, but have gone with 9 to factor in the upmix, which is still great none the less.