An economic manner to purchase the first two albums by PBS.
Taking into account that the two records aren't that very long anyway, to put them both on one CD makes sense in that way.
The disadvantage is that one isn't able to distinguish the 'personality' of each record from the other because they are together. It helps that, on the back, the different album are 'identified' by separating the tracks, on on the left, the other on the right. As to the quality of the music, both albums are what they were, innovative and wholy memorable, especially for those who enjoyed PBS.
The booklet included isn't extraordinary. It lists the lyrics to the first album and not much else. Probably by purchasing the CDs separately, one might get more complete documentation but that's not a given.