I got this set on LP even though I had all the first three albums already. I got it on tape when I found it cheap even though I'd bought all the first three albums on tape already. I don't have Hergest Ridge on CD yet, and I'm thinking maybe I'll get this set instead even though I have the other two albums on CD already.
Why? Well, the sound quality is vastly improved, for one thing. This set showed me what a difference remixing could make. The tonal balance on Ommadawn is much more subtle, and the effect consequently greater, than the original album. The original version of the hornpipe at the end of TB was great fun and to my mind remains so.
What clinched it for me, though, was the bonus album, "Collaborations." There are some lovely pieces on this album, some taken from albums by the composer David Bedford which might be hard to find nowadays, some singles (e.g. "Portsmouth"), one of the most searingly intense piano-guitar duets I have ever heard ("First Excursion"), and finally the sublime vocal stylings of Messrs. Oldfield and Bedford on "Speak (Tho' You Only Say Farewell)." You cannot miss this tour de force.
I loved this collection. Still do....